diff --git a/LeetcodeProblems/Algorithms/2Sum.js b/LeetcodeProblems/Algorithms/easy/2Sum.js
similarity index 100%
rename from LeetcodeProblems/Algorithms/2Sum.js
rename to LeetcodeProblems/Algorithms/easy/2Sum.js
diff --git a/LeetcodeProblems/Algorithms/Award_Budget_Cuts.js b/LeetcodeProblems/Algorithms/easy/Award_Budget_Cuts.js
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rename from LeetcodeProblems/Algorithms/Award_Budget_Cuts.js
rename to LeetcodeProblems/Algorithms/easy/Award_Budget_Cuts.js
diff --git a/LeetcodeProblems/Algorithms/Backspace_String_Compare.js b/LeetcodeProblems/Algorithms/easy/Backspace_String_Compare.js
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diff --git a/LeetcodeProblems/Algorithms/Binary_Gap.js b/LeetcodeProblems/Algorithms/easy/Binary_Gap.js
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diff --git a/LeetcodeProblems/Algorithms/Deletion_Distance.js b/LeetcodeProblems/Algorithms/easy/Deletion_Distance.js
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rename to LeetcodeProblems/Algorithms/easy/Deletion_Distance.js
diff --git a/LeetcodeProblems/Algorithms/Flood_Fill.js b/LeetcodeProblems/Algorithms/easy/Flood_Fill.js
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diff --git a/LeetcodeProblems/Algorithms/Happy_Number.js b/LeetcodeProblems/Algorithms/easy/Happy_Number.js
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diff --git a/LeetcodeProblems/Algorithms/Implement_stack_using_queues.js b/LeetcodeProblems/Algorithms/easy/Implement_stack_using_queues.js
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diff --git a/LeetcodeProblems/Algorithms/Longest_Common_Prefix.js b/LeetcodeProblems/Algorithms/easy/Longest_Common_Prefix.js
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diff --git a/LeetcodeProblems/Algorithms/Majority_Element.js b/LeetcodeProblems/Algorithms/easy/Majority_Element.js
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diff --git a/LeetcodeProblems/Algorithms/Maximun_Subarray.js b/LeetcodeProblems/Algorithms/easy/Maximun_Subarray.js
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diff --git a/LeetcodeProblems/Algorithms/Min_Stack.js b/LeetcodeProblems/Algorithms/easy/Min_Stack.js
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rename to LeetcodeProblems/Algorithms/easy/Min_Stack.js
diff --git a/LeetcodeProblems/Algorithms/Number_of_Segments_in_a_String.js b/LeetcodeProblems/Algorithms/easy/Number_of_Segments_in_a_String.js
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rename from LeetcodeProblems/Algorithms/Number_of_Segments_in_a_String.js
rename to LeetcodeProblems/Algorithms/easy/Number_of_Segments_in_a_String.js
diff --git a/LeetcodeProblems/Algorithms/Reverse_String_II.js b/LeetcodeProblems/Algorithms/easy/Reverse_String_II.js
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diff --git a/LeetcodeProblems/Algorithms/Same_Tree.js b/LeetcodeProblems/Algorithms/easy/Same_Tree.js
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diff --git a/LeetcodeProblems/Algorithms/Shuffle_String.js b/LeetcodeProblems/Algorithms/easy/Shuffle_String.js
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diff --git a/LeetcodeProblems/Algorithms/Sum_Of_Square_Numbers.js b/LeetcodeProblems/Algorithms/easy/Sum_Of_Square_Numbers.js
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diff --git a/LeetcodeProblems/Algorithms/Symmetric_Tree.js b/LeetcodeProblems/Algorithms/easy/Symmetric_Tree.js
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rename from LeetcodeProblems/Algorithms/Symmetric_Tree.js
rename to LeetcodeProblems/Algorithms/easy/Symmetric_Tree.js
diff --git a/LeetcodeProblems/Algorithms/Tic_Tac_Toe.js b/LeetcodeProblems/Algorithms/easy/Tic_Tac_Toe.js
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rename from LeetcodeProblems/Algorithms/Tic_Tac_Toe.js
rename to LeetcodeProblems/Algorithms/easy/Tic_Tac_Toe.js
diff --git a/LeetcodeProblems/Algorithms/Valid_Parentheses.js b/LeetcodeProblems/Algorithms/easy/Valid_Parentheses.js
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rename from LeetcodeProblems/Algorithms/Valid_Parentheses.js
rename to LeetcodeProblems/Algorithms/easy/Valid_Parentheses.js
diff --git a/LeetcodeProblems/Algorithms/Edit_Distance.js b/LeetcodeProblems/Algorithms/hard/Edit_Distance.js
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rename from LeetcodeProblems/Algorithms/Edit_Distance.js
rename to LeetcodeProblems/Algorithms/hard/Edit_Distance.js
diff --git a/LeetcodeProblems/Algorithms/Longest_Consecutive_Sequence.js b/LeetcodeProblems/Algorithms/hard/Longest_Consecutive_Sequence.js
similarity index 100%
rename from LeetcodeProblems/Algorithms/Longest_Consecutive_Sequence.js
rename to LeetcodeProblems/Algorithms/hard/Longest_Consecutive_Sequence.js
diff --git a/LeetcodeProblems/Algorithms/Minimum_Window_Substring.js b/LeetcodeProblems/Algorithms/hard/Minimum_Window_Substring.js
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rename from LeetcodeProblems/Algorithms/Minimum_Window_Substring.js
rename to LeetcodeProblems/Algorithms/hard/Minimum_Window_Substring.js
diff --git a/LeetcodeProblems/Algorithms/NQueens.js b/LeetcodeProblems/Algorithms/hard/NQueens.js
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rename from LeetcodeProblems/Algorithms/NQueens.js
rename to LeetcodeProblems/Algorithms/hard/NQueens.js
diff --git a/LeetcodeProblems/Algorithms/Regular_Expression_Matching.js b/LeetcodeProblems/Algorithms/hard/Regular_Expression_Matching.js
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rename from LeetcodeProblems/Algorithms/Regular_Expression_Matching.js
rename to LeetcodeProblems/Algorithms/hard/Regular_Expression_Matching.js
diff --git a/LeetcodeProblems/Algorithms/Remove_Invalid_Parentheses.js b/LeetcodeProblems/Algorithms/hard/Remove_Invalid_Parentheses.js
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rename from LeetcodeProblems/Algorithms/Remove_Invalid_Parentheses.js
rename to LeetcodeProblems/Algorithms/hard/Remove_Invalid_Parentheses.js
diff --git a/LeetcodeProblems/Algorithms/Set_Matrix_Zeroes.js b/LeetcodeProblems/Algorithms/hard/Set_Matrix_Zeroes.js
similarity index 100%
rename from LeetcodeProblems/Algorithms/Set_Matrix_Zeroes.js
rename to LeetcodeProblems/Algorithms/hard/Set_Matrix_Zeroes.js
diff --git a/LeetcodeProblems/Algorithms/merge_k_sorted_lists.js b/LeetcodeProblems/Algorithms/hard/merge_k_sorted_lists.js
similarity index 100%
rename from LeetcodeProblems/Algorithms/merge_k_sorted_lists.js
rename to LeetcodeProblems/Algorithms/hard/merge_k_sorted_lists.js
diff --git a/LeetcodeProblems/Algorithms/3Sum.js b/LeetcodeProblems/Algorithms/medium/3Sum.js
similarity index 100%
rename from LeetcodeProblems/Algorithms/3Sum.js
rename to LeetcodeProblems/Algorithms/medium/3Sum.js
diff --git a/LeetcodeProblems/Algorithms/3SumClosest.js b/LeetcodeProblems/Algorithms/medium/3SumClosest.js
similarity index 100%
rename from LeetcodeProblems/Algorithms/3SumClosest.js
rename to LeetcodeProblems/Algorithms/medium/3SumClosest.js
diff --git a/LeetcodeProblems/Algorithms/Add_Two_Numbers.js b/LeetcodeProblems/Algorithms/medium/Add_Two_Numbers.js
similarity index 95%
rename from LeetcodeProblems/Algorithms/Add_Two_Numbers.js
rename to LeetcodeProblems/Algorithms/medium/Add_Two_Numbers.js
index 2169716..3daed64 100644
--- a/LeetcodeProblems/Algorithms/Add_Two_Numbers.js
+++ b/LeetcodeProblems/Algorithms/medium/Add_Two_Numbers.js
@@ -21,7 +21,7 @@ Explanation: 342 + 465 = 807.
  *     this.next = null;
  * }
  */
-var ListNode = require("../../UtilsClasses/ListNode").ListNode;
+var ListNode = require("../../../UtilsClasses/ListNode").ListNode;
 
 /**
  * @param {ListNode} l1
diff --git a/LeetcodeProblems/Algorithms/Best_Time_To_Buy_And_Sell_Stock_II.js b/LeetcodeProblems/Algorithms/medium/Best_Time_To_Buy_And_Sell_Stock_II.js
similarity index 100%
rename from LeetcodeProblems/Algorithms/Best_Time_To_Buy_And_Sell_Stock_II.js
rename to LeetcodeProblems/Algorithms/medium/Best_Time_To_Buy_And_Sell_Stock_II.js
diff --git a/LeetcodeProblems/Algorithms/Clone_Graph.js b/LeetcodeProblems/Algorithms/medium/Clone_Graph.js
similarity index 100%
rename from LeetcodeProblems/Algorithms/Clone_Graph.js
rename to LeetcodeProblems/Algorithms/medium/Clone_Graph.js
diff --git a/LeetcodeProblems/Algorithms/Coin_Change.js b/LeetcodeProblems/Algorithms/medium/Coin_Change.js
similarity index 100%
rename from LeetcodeProblems/Algorithms/Coin_Change.js
rename to LeetcodeProblems/Algorithms/medium/Coin_Change.js
diff --git a/LeetcodeProblems/Algorithms/Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal.js b/LeetcodeProblems/Algorithms/medium/Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal.js
similarity index 95%
rename from LeetcodeProblems/Algorithms/Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal.js
rename to LeetcodeProblems/Algorithms/medium/Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal.js
index 310624b..021301b 100644
--- a/LeetcodeProblems/Algorithms/Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal.js
+++ b/LeetcodeProblems/Algorithms/medium/Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal.js
@@ -27,7 +27,7 @@ Return the following binary tree:
  *     this.left = this.right = null;
  * }
  */
-var TreeNode = require("../../UtilsClasses/TreeNode").TreeNode;
+var TreeNode = require("../../../UtilsClasses/TreeNode").TreeNode;
 
 /**
  * @param {number[]} preorder
diff --git a/LeetcodeProblems/Algorithms/Container_With_Most_Water.js b/LeetcodeProblems/Algorithms/medium/Container_With_Most_Water.js
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rename from LeetcodeProblems/Algorithms/Container_With_Most_Water.js
rename to LeetcodeProblems/Algorithms/medium/Container_With_Most_Water.js
diff --git a/LeetcodeProblems/Algorithms/Design_Circular_Deque.js b/LeetcodeProblems/Algorithms/medium/Design_Circular_Deque.js
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rename from LeetcodeProblems/Algorithms/Design_Circular_Deque.js
rename to LeetcodeProblems/Algorithms/medium/Design_Circular_Deque.js
diff --git a/LeetcodeProblems/Algorithms/Escape_The_Ghosts.js b/LeetcodeProblems/Algorithms/medium/Escape_The_Ghosts.js
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rename from LeetcodeProblems/Algorithms/Escape_The_Ghosts.js
rename to LeetcodeProblems/Algorithms/medium/Escape_The_Ghosts.js
diff --git a/LeetcodeProblems/Algorithms/Find_Anagrams.js b/LeetcodeProblems/Algorithms/medium/Find_Anagrams.js
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rename from LeetcodeProblems/Algorithms/Find_Anagrams.js
rename to LeetcodeProblems/Algorithms/medium/Find_Anagrams.js
diff --git a/LeetcodeProblems/Algorithms/Find_Subarrays_With_Equal_Sum.js b/LeetcodeProblems/Algorithms/medium/Find_Subarrays_With_Equal_Sum.js
similarity index 100%
rename from LeetcodeProblems/Algorithms/Find_Subarrays_With_Equal_Sum.js
rename to LeetcodeProblems/Algorithms/medium/Find_Subarrays_With_Equal_Sum.js
diff --git a/LeetcodeProblems/Algorithms/Gas_Station.js b/LeetcodeProblems/Algorithms/medium/Gas_Station.js
similarity index 100%
rename from LeetcodeProblems/Algorithms/Gas_Station.js
rename to LeetcodeProblems/Algorithms/medium/Gas_Station.js
diff --git a/LeetcodeProblems/Algorithms/Generate_Parenthesis.js b/LeetcodeProblems/Algorithms/medium/Generate_Parenthesis.js
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rename from LeetcodeProblems/Algorithms/Generate_Parenthesis.js
rename to LeetcodeProblems/Algorithms/medium/Generate_Parenthesis.js
diff --git a/LeetcodeProblems/Algorithms/Group_Anagrams.js b/LeetcodeProblems/Algorithms/medium/Group_Anagrams.js
similarity index 100%
rename from LeetcodeProblems/Algorithms/Group_Anagrams.js
rename to LeetcodeProblems/Algorithms/medium/Group_Anagrams.js
diff --git a/LeetcodeProblems/Algorithms/K_Closest_Points_to_Origin.js b/LeetcodeProblems/Algorithms/medium/K_Closest_Points_to_Origin.js
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rename from LeetcodeProblems/Algorithms/K_Closest_Points_to_Origin.js
rename to LeetcodeProblems/Algorithms/medium/K_Closest_Points_to_Origin.js
diff --git a/LeetcodeProblems/Algorithms/Kth_Largest_Element_in_an_Array.js b/LeetcodeProblems/Algorithms/medium/Kth_Largest_Element_in_an_Array.js
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rename from LeetcodeProblems/Algorithms/Kth_Largest_Element_in_an_Array.js
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diff --git a/LeetcodeProblems/Algorithms/Linked_List_Cycle_II.js b/LeetcodeProblems/Algorithms/medium/Linked_List_Cycle_II.js
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rename from LeetcodeProblems/Algorithms/Linked_List_Cycle_II.js
rename to LeetcodeProblems/Algorithms/medium/Linked_List_Cycle_II.js
diff --git a/LeetcodeProblems/Algorithms/Longest_Palindromic_Substring.js b/LeetcodeProblems/Algorithms/medium/Longest_Palindromic_Substring.js
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rename from LeetcodeProblems/Algorithms/Longest_Palindromic_Substring.js
rename to LeetcodeProblems/Algorithms/medium/Longest_Palindromic_Substring.js
diff --git a/LeetcodeProblems/Algorithms/Longest_Substring.js b/LeetcodeProblems/Algorithms/medium/Longest_Substring.js
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rename from LeetcodeProblems/Algorithms/Longest_Substring.js
rename to LeetcodeProblems/Algorithms/medium/Longest_Substring.js
diff --git a/LeetcodeProblems/Algorithms/Lowest_Common_Ancestor_of_a_Binary_Tree.js b/LeetcodeProblems/Algorithms/medium/Lowest_Common_Ancestor_of_a_Binary_Tree.js
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rename from LeetcodeProblems/Algorithms/Lowest_Common_Ancestor_of_a_Binary_Tree.js
rename to LeetcodeProblems/Algorithms/medium/Lowest_Common_Ancestor_of_a_Binary_Tree.js
diff --git a/LeetcodeProblems/Algorithms/Max_Area_Of_Island.js b/LeetcodeProblems/Algorithms/medium/Max_Area_Of_Island.js
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rename from LeetcodeProblems/Algorithms/Max_Area_Of_Island.js
rename to LeetcodeProblems/Algorithms/medium/Max_Area_Of_Island.js
diff --git a/LeetcodeProblems/Algorithms/Max_Consecutive_Ones_III.js b/LeetcodeProblems/Algorithms/medium/Max_Consecutive_Ones_III.js
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rename from LeetcodeProblems/Algorithms/Max_Consecutive_Ones_III.js
rename to LeetcodeProblems/Algorithms/medium/Max_Consecutive_Ones_III.js
diff --git a/LeetcodeProblems/Algorithms/Maximal_Square.js b/LeetcodeProblems/Algorithms/medium/Maximal_Square.js
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rename from LeetcodeProblems/Algorithms/Maximal_Square.js
rename to LeetcodeProblems/Algorithms/medium/Maximal_Square.js
diff --git a/LeetcodeProblems/Algorithms/Maximise_Hour_Glass_Sum.js b/LeetcodeProblems/Algorithms/medium/Maximise_Hour_Glass_Sum.js
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rename from LeetcodeProblems/Algorithms/Maximise_Hour_Glass_Sum.js
rename to LeetcodeProblems/Algorithms/medium/Maximise_Hour_Glass_Sum.js
diff --git a/LeetcodeProblems/Algorithms/Minimize_Maximum_Pair_Sum_In_Array.js b/LeetcodeProblems/Algorithms/medium/Minimize_Maximum_Pair_Sum_In_Array.js
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rename from LeetcodeProblems/Algorithms/Minimize_Maximum_Pair_Sum_In_Array.js
rename to LeetcodeProblems/Algorithms/medium/Minimize_Maximum_Pair_Sum_In_Array.js
diff --git a/LeetcodeProblems/Algorithms/Minimum_Add_To_Make_Parentheses_Valid.js b/LeetcodeProblems/Algorithms/medium/Minimum_Add_To_Make_Parentheses_Valid.js
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diff --git a/LeetcodeProblems/Algorithms/Minimum_Size_Subarray.js b/LeetcodeProblems/Algorithms/medium/Minimum_Size_Subarray.js
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rename to LeetcodeProblems/Algorithms/medium/Minimum_Size_Subarray.js
diff --git a/LeetcodeProblems/Algorithms/Next_Permutation.js b/LeetcodeProblems/Algorithms/medium/Next_Permutation.js
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diff --git a/LeetcodeProblems/Algorithms/Number_of_Islands.js b/LeetcodeProblems/Algorithms/medium/Number_of_Islands.js
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diff --git a/LeetcodeProblems/Algorithms/Permutations_Without_Duplicates.js b/LeetcodeProblems/Algorithms/medium/Permutations_Without_Duplicates.js
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rename from LeetcodeProblems/Algorithms/Permutations_Without_Duplicates.js
rename to LeetcodeProblems/Algorithms/medium/Permutations_Without_Duplicates.js
diff --git a/LeetcodeProblems/Algorithms/Restore_IP_Addresses.js b/LeetcodeProblems/Algorithms/medium/Restore_IP_Addresses.js
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rename from LeetcodeProblems/Algorithms/Restore_IP_Addresses.js
rename to LeetcodeProblems/Algorithms/medium/Restore_IP_Addresses.js
diff --git a/LeetcodeProblems/Algorithms/Reverse_Integer.js b/LeetcodeProblems/Algorithms/medium/Reverse_Integer.js
similarity index 100%
rename from LeetcodeProblems/Algorithms/Reverse_Integer.js
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diff --git a/LeetcodeProblems/Algorithms/SearchIng_Rotated_Sorted_Array.js b/LeetcodeProblems/Algorithms/medium/SearchIng_Rotated_Sorted_Array.js
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rename from LeetcodeProblems/Algorithms/SearchIng_Rotated_Sorted_Array.js
rename to LeetcodeProblems/Algorithms/medium/SearchIng_Rotated_Sorted_Array.js
diff --git a/LeetcodeProblems/Algorithms/Search_a_2D_Matrix.js b/LeetcodeProblems/Algorithms/medium/Search_a_2D_Matrix.js
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rename from LeetcodeProblems/Algorithms/Search_a_2D_Matrix.js
rename to LeetcodeProblems/Algorithms/medium/Search_a_2D_Matrix.js
diff --git a/LeetcodeProblems/Algorithms/Search_a_2D_Matrix_II.js b/LeetcodeProblems/Algorithms/medium/Search_a_2D_Matrix_II.js
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rename from LeetcodeProblems/Algorithms/Search_a_2D_Matrix_II.js
rename to LeetcodeProblems/Algorithms/medium/Search_a_2D_Matrix_II.js
diff --git a/LeetcodeProblems/Algorithms/Simplify_Path.js b/LeetcodeProblems/Algorithms/medium/Simplify_Path.js
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rename from LeetcodeProblems/Algorithms/Simplify_Path.js
rename to LeetcodeProblems/Algorithms/medium/Simplify_Path.js
diff --git a/LeetcodeProblems/Algorithms/Spiral_Matrix.js b/LeetcodeProblems/Algorithms/medium/Spiral_Matrix.js
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rename from LeetcodeProblems/Algorithms/Spiral_Matrix.js
rename to LeetcodeProblems/Algorithms/medium/Spiral_Matrix.js
diff --git a/LeetcodeProblems/Algorithms/Subarray_Sum_Equals_K.js b/LeetcodeProblems/Algorithms/medium/Subarray_Sum_Equals_K.js
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rename from LeetcodeProblems/Algorithms/Subarray_Sum_Equals_K.js
rename to LeetcodeProblems/Algorithms/medium/Subarray_Sum_Equals_K.js
diff --git a/LeetcodeProblems/Algorithms/Subsets.js b/LeetcodeProblems/Algorithms/medium/Subsets.js
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rename from LeetcodeProblems/Algorithms/Subsets.js
rename to LeetcodeProblems/Algorithms/medium/Subsets.js
diff --git a/LeetcodeProblems/Algorithms/Swap_Nodes_In_Pairs.js b/LeetcodeProblems/Algorithms/medium/Swap_Nodes_In_Pairs.js
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rename from LeetcodeProblems/Algorithms/Swap_Nodes_In_Pairs.js
rename to LeetcodeProblems/Algorithms/medium/Swap_Nodes_In_Pairs.js
diff --git a/LeetcodeProblems/Algorithms/Time_Needed_Rearrange_Binary_String.js b/LeetcodeProblems/Algorithms/medium/Time_Needed_Rearrange_Binary_String.js
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rename from LeetcodeProblems/Algorithms/Time_Needed_Rearrange_Binary_String.js
rename to LeetcodeProblems/Algorithms/medium/Time_Needed_Rearrange_Binary_String.js
diff --git a/LeetcodeProblems/Algorithms/Top_K_Frequent_Elements.js b/LeetcodeProblems/Algorithms/medium/Top_K_Frequent_Elements.js
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rename from LeetcodeProblems/Algorithms/Top_K_Frequent_Elements.js
rename to LeetcodeProblems/Algorithms/medium/Top_K_Frequent_Elements.js
diff --git a/LeetcodeProblems/Algorithms/Unique_Binary_Search_Trees.js b/LeetcodeProblems/Algorithms/medium/Unique_Binary_Search_Trees.js
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diff --git a/LeetcodeProblems/Algorithms/Verify_Preorder_Serialization_of_a_Binary_Tree.js b/LeetcodeProblems/Algorithms/medium/Verify_Preorder_Serialization_of_a_Binary_Tree.js
similarity index 100%
rename from LeetcodeProblems/Algorithms/Verify_Preorder_Serialization_of_a_Binary_Tree.js
rename to LeetcodeProblems/Algorithms/medium/Verify_Preorder_Serialization_of_a_Binary_Tree.js
diff --git a/LeetcodeProblems/Databases/Classes_More_Than_5_Students.sql b/LeetcodeProblems/Databases/easy/Classes_More_Than_5_Students.sql
similarity index 100%
rename from LeetcodeProblems/Databases/Classes_More_Than_5_Students.sql
rename to LeetcodeProblems/Databases/easy/Classes_More_Than_5_Students.sql
diff --git a/LeetcodeProblems/Databases/Combine_Two_Tables.sql b/LeetcodeProblems/Databases/easy/Combine_Two_Tables.sql
similarity index 100%
rename from LeetcodeProblems/Databases/Combine_Two_Tables.sql
rename to LeetcodeProblems/Databases/easy/Combine_Two_Tables.sql
diff --git a/LeetcodeProblems/Databases/Customers_Who_Never_Order.sql b/LeetcodeProblems/Databases/easy/Customers_Who_Never_Order.sql
similarity index 100%
rename from LeetcodeProblems/Databases/Customers_Who_Never_Order.sql
rename to LeetcodeProblems/Databases/easy/Customers_Who_Never_Order.sql
diff --git a/LeetcodeProblems/Databases/Delete_Duplicate_Emails.sql b/LeetcodeProblems/Databases/easy/Delete_Duplicate_Emails.sql
similarity index 100%
rename from LeetcodeProblems/Databases/Delete_Duplicate_Emails.sql
rename to LeetcodeProblems/Databases/easy/Delete_Duplicate_Emails.sql
diff --git a/LeetcodeProblems/Databases/Duplicate_emails.sql b/LeetcodeProblems/Databases/easy/Duplicate_emails.sql
similarity index 100%
rename from LeetcodeProblems/Databases/Duplicate_emails.sql
rename to LeetcodeProblems/Databases/easy/Duplicate_emails.sql
diff --git a/LeetcodeProblems/Databases/Employees_Earning_More_Than_Their_Managers.sql b/LeetcodeProblems/Databases/easy/Employees_Earning_More_Than_Their_Managers.sql
similarity index 100%
rename from LeetcodeProblems/Databases/Employees_Earning_More_Than_Their_Managers.sql
rename to LeetcodeProblems/Databases/easy/Employees_Earning_More_Than_Their_Managers.sql
diff --git a/LeetcodeProblems/Databases/Reformat_Department_Table.sql b/LeetcodeProblems/Databases/easy/Reformat_Department_Table.sql
similarity index 100%
rename from LeetcodeProblems/Databases/Reformat_Department_Table.sql
rename to LeetcodeProblems/Databases/easy/Reformat_Department_Table.sql
diff --git a/LeetcodeProblems/Databases/Rising_Temperature.sql b/LeetcodeProblems/Databases/easy/Rising_Temperature.sql
similarity index 100%
rename from LeetcodeProblems/Databases/Rising_Temperature.sql
rename to LeetcodeProblems/Databases/easy/Rising_Temperature.sql
diff --git a/LeetcodeProblems/Databases/Second_highest_salary.sql b/LeetcodeProblems/Databases/easy/Second_highest_salary.sql
similarity index 100%
rename from LeetcodeProblems/Databases/Second_highest_salary.sql
rename to LeetcodeProblems/Databases/easy/Second_highest_salary.sql
diff --git a/LeetcodeProblems/Databases/Human_Traffic_of_Stadium.sql b/LeetcodeProblems/Databases/hard/Human_Traffic_of_Stadium.sql
similarity index 100%
rename from LeetcodeProblems/Databases/Human_Traffic_of_Stadium.sql
rename to LeetcodeProblems/Databases/hard/Human_Traffic_of_Stadium.sql
diff --git a/LeetcodeProblems/Databases/Trips_and_Users.sql b/LeetcodeProblems/Databases/hard/Trips_and_Users.sql
similarity index 100%
rename from LeetcodeProblems/Databases/Trips_and_Users.sql
rename to LeetcodeProblems/Databases/hard/Trips_and_Users.sql
diff --git a/LeetcodeProblems/Databases/Consecutive_Numbers.sql b/LeetcodeProblems/Databases/medium/Consecutive_Numbers.sql
similarity index 100%
rename from LeetcodeProblems/Databases/Consecutive_Numbers.sql
rename to LeetcodeProblems/Databases/medium/Consecutive_Numbers.sql
diff --git a/LeetcodeProblems/Databases/Department_Highest_Salary.sql b/LeetcodeProblems/Databases/medium/Department_Highest_Salary.sql
similarity index 100%
rename from LeetcodeProblems/Databases/Department_Highest_Salary.sql
rename to LeetcodeProblems/Databases/medium/Department_Highest_Salary.sql
diff --git a/LeetcodeProblems/Databases/Exchange_Seats.sql b/LeetcodeProblems/Databases/medium/Exchange_Seats.sql
similarity index 100%
rename from LeetcodeProblems/Databases/Exchange_Seats.sql
rename to LeetcodeProblems/Databases/medium/Exchange_Seats.sql
diff --git a/LeetcodeProblems/Databases/Rank_Scores.sql b/LeetcodeProblems/Databases/medium/Rank_Scores.sql
similarity index 100%
rename from LeetcodeProblems/Databases/Rank_Scores.sql
rename to LeetcodeProblems/Databases/medium/Rank_Scores.sql
diff --git a/LeetcodeProblems/Databases/nth_Highest_Salary.sql b/LeetcodeProblems/Databases/medium/nth_Highest_Salary.sql
similarity index 100%
rename from LeetcodeProblems/Databases/nth_Highest_Salary.sql
rename to LeetcodeProblems/Databases/medium/nth_Highest_Salary.sql
diff --git a/LeetcodeProblemsTests/Algorithms/2Sum_Test.js b/LeetcodeProblemsTests/Algorithms/easy/2Sum_Test.js
similarity index 75%
rename from LeetcodeProblemsTests/Algorithms/2Sum_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/2Sum_Test.js
index 19f8ce0..2fd2dbc 100644
--- a/LeetcodeProblemsTests/Algorithms/2Sum_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/easy/2Sum_Test.js
@@ -1,7 +1,6 @@
 const assert = require("assert");
-const twoSum = require("../../LeetcodeProblems/Algorithms/2Sum").twoSum;
-const twoSum2 = require("../../LeetcodeProblems/Algorithms/2Sum").twoSum2;
-
+const twoSum = require("../../../LeetcodeProblems/Algorithms/easy/2Sum").twoSum;
+const twoSum2 = require("../../../LeetcodeProblems/Algorithms/easy/2Sum").twoSum2;
 
 var testFirstSolution = function () {
   assert.deepEqual([0,1], twoSum([2,7,11,15], 9));
diff --git a/LeetcodeProblemsTests/Algorithms/Award_Budget_Cuts_Test.js b/LeetcodeProblemsTests/Algorithms/easy/Award_Budget_Cuts_Test.js
similarity index 71%
rename from LeetcodeProblemsTests/Algorithms/Award_Budget_Cuts_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/Award_Budget_Cuts_Test.js
index 2dacf4a..797fb52 100644
--- a/LeetcodeProblemsTests/Algorithms/Award_Budget_Cuts_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/easy/Award_Budget_Cuts_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const cutAwardBadges = require("../../LeetcodeProblems/Algorithms/Award_Budget_Cuts").cutAwardBadges;
+const cutAwardBadges = require("../../../LeetcodeProblems/Algorithms/easy/Award_Budget_Cuts").cutAwardBadges;
 
 function test() {
   assert.deepEqual(
diff --git a/LeetcodeProblemsTests/Algorithms/Backspace_String_Compare_Test.js b/LeetcodeProblemsTests/Algorithms/easy/Backspace_String_Compare_Test.js
similarity index 71%
rename from LeetcodeProblemsTests/Algorithms/Backspace_String_Compare_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/Backspace_String_Compare_Test.js
index 22fbc39..4b73dfe 100644
--- a/LeetcodeProblemsTests/Algorithms/Backspace_String_Compare_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/easy/Backspace_String_Compare_Test.js
@@ -1,6 +1,6 @@
 const assert = require("assert");
-const backspaceCompare = require("../../LeetcodeProblems/Algorithms/Backspace_String_Compare").backspaceCompare;
-const backspaceCompare2 = require("../../LeetcodeProblems/Algorithms/Backspace_String_Compare").backspaceCompare2;
+const backspaceCompare = require("../../../LeetcodeProblems/Algorithms/easy/Backspace_String_Compare").backspaceCompare;
+const backspaceCompare2 = require("../../../LeetcodeProblems/Algorithms/easy/Backspace_String_Compare").backspaceCompare2;
 
 function test() {
   assert.equal(backspaceCompare("ab#c", "ad#c"), true); // true
diff --git a/LeetcodeProblemsTests/Algorithms/Binary_Gap_Test.js b/LeetcodeProblemsTests/Algorithms/easy/Binary_Gap_Test.js
similarity index 64%
rename from LeetcodeProblemsTests/Algorithms/Binary_Gap_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/Binary_Gap_Test.js
index 6025822..c89a4a6 100644
--- a/LeetcodeProblemsTests/Algorithms/Binary_Gap_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/easy/Binary_Gap_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const binaryGap = require("../../LeetcodeProblems/Algorithms/Binary_Gap").binaryGap;
+const binaryGap = require("../../../LeetcodeProblems/Algorithms/easy/Binary_Gap").binaryGap;
 
 function test() {
   assert.equal(binaryGap(22), 2); // 10110
diff --git a/LeetcodeProblemsTests/Algorithms/Deletion_Distance_Test.js b/LeetcodeProblemsTests/Algorithms/easy/Deletion_Distance_Test.js
similarity index 67%
rename from LeetcodeProblemsTests/Algorithms/Deletion_Distance_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/Deletion_Distance_Test.js
index d1ae378..7ac3d80 100644
--- a/LeetcodeProblemsTests/Algorithms/Deletion_Distance_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/easy/Deletion_Distance_Test.js
@@ -1,7 +1,7 @@
 const assert = require("assert");
-var deletionDistance = require("../../LeetcodeProblems/Algorithms/Deletion_Distance").deletionDistance;
-var deletionDistance2 = require("../../LeetcodeProblems/Algorithms/Deletion_Distance").deletionDistance2;
-var deletionDistanceDP = require("../../LeetcodeProblems/Algorithms/Deletion_Distance").deletionDistanceDP;
+var deletionDistance = require("../../../LeetcodeProblems/Algorithms/easy/Deletion_Distance").deletionDistance;
+var deletionDistance2 = require("../../../LeetcodeProblems/Algorithms/easy/Deletion_Distance").deletionDistance2;
+var deletionDistanceDP = require("../../../LeetcodeProblems/Algorithms/easy/Deletion_Distance").deletionDistanceDP;
 
 function test() {
   assert.equal(deletionDistance("dog", "frog"), 3);
diff --git a/LeetcodeProblemsTests/Algorithms/Flood_Fill_Test.js b/LeetcodeProblemsTests/Algorithms/easy/Flood_Fill_Test.js
similarity index 68%
rename from LeetcodeProblemsTests/Algorithms/Flood_Fill_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/Flood_Fill_Test.js
index 447795f..557af9f 100644
--- a/LeetcodeProblemsTests/Algorithms/Flood_Fill_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/easy/Flood_Fill_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const floodFill = require("../../LeetcodeProblems/Algorithms/Flood_Fill").floodFill;
+const floodFill = require("../../../LeetcodeProblems/Algorithms/easy/Flood_Fill").floodFill;
 
 function test() {
   assert.deepEqual(
diff --git a/LeetcodeProblemsTests/Algorithms/Happy_Number_Test.js b/LeetcodeProblemsTests/Algorithms/easy/Happy_Number_Test.js
similarity index 63%
rename from LeetcodeProblemsTests/Algorithms/Happy_Number_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/Happy_Number_Test.js
index fa4544d..00e198a 100644
--- a/LeetcodeProblemsTests/Algorithms/Happy_Number_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/easy/Happy_Number_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const isHappy = require("../../LeetcodeProblems/Algorithms/Happy_Number").isHappy;
+const isHappy = require("../../../LeetcodeProblems/Algorithms/easy/Happy_Number").isHappy;
 
 var test = function () {
   assert.equal(isHappy(19),true);
diff --git a/LeetcodeProblemsTests/Algorithms/Implement_stack_using_queues_Test.js b/LeetcodeProblemsTests/Algorithms/easy/Implement_stack_using_queues_Test.js
similarity index 79%
rename from LeetcodeProblemsTests/Algorithms/Implement_stack_using_queues_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/Implement_stack_using_queues_Test.js
index 8e3fb3a..a5d1735 100644
--- a/LeetcodeProblemsTests/Algorithms/Implement_stack_using_queues_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/easy/Implement_stack_using_queues_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const MyStack = require("../../LeetcodeProblems/Algorithms/Implement_stack_using_queues").MyStack;
+const MyStack = require("../../../LeetcodeProblems/Algorithms/easy/Implement_stack_using_queues").MyStack;
 
 var test = function () {
   var myStack = new MyStack();
diff --git a/LeetcodeProblemsTests/Algorithms/Longest_Common_Prefix_Test.js b/LeetcodeProblemsTests/Algorithms/easy/Longest_Common_Prefix_Test.js
similarity index 68%
rename from LeetcodeProblemsTests/Algorithms/Longest_Common_Prefix_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/Longest_Common_Prefix_Test.js
index 92c6c7a..7a7109a 100644
--- a/LeetcodeProblemsTests/Algorithms/Longest_Common_Prefix_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/easy/Longest_Common_Prefix_Test.js
@@ -1,6 +1,6 @@
 
 const assert = require("assert");
-const longestCommonPrefix = require("../../LeetcodeProblems/Algorithms/Longest_Common_Prefix").longestCommonPrefix;
+const longestCommonPrefix = require("../../../LeetcodeProblems/Algorithms/easy/Longest_Common_Prefix").longestCommonPrefix;
 
 function test() {
   assert.equal(longestCommonPrefix(["flower","flow","flight"]), "fl");
diff --git a/LeetcodeProblemsTests/Algorithms/Majority_Element_Test.js b/LeetcodeProblemsTests/Algorithms/easy/Majority_Element_Test.js
similarity index 68%
rename from LeetcodeProblemsTests/Algorithms/Majority_Element_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/Majority_Element_Test.js
index b9420d2..96c08b8 100644
--- a/LeetcodeProblemsTests/Algorithms/Majority_Element_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/easy/Majority_Element_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const majorityElement = require("../../LeetcodeProblems/Algorithms/Majority_Element").majorityElement;
+const majorityElement = require("../../../LeetcodeProblems/Algorithms/easy/Majority_Element").majorityElement;
 
 function test() {
   assert.equal(majorityElement([2,2,3]), 2);
diff --git a/LeetcodeProblemsTests/Algorithms/Maximun_Subarray_Test.js b/LeetcodeProblemsTests/Algorithms/easy/Maximun_Subarray_Test.js
similarity index 70%
rename from LeetcodeProblemsTests/Algorithms/Maximun_Subarray_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/Maximun_Subarray_Test.js
index 68fd57e..d408555 100644
--- a/LeetcodeProblemsTests/Algorithms/Maximun_Subarray_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/easy/Maximun_Subarray_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const maxSubArray = require("../../LeetcodeProblems/Algorithms/Maximun_Subarray").maxSubArray;
+const maxSubArray = require("../../../LeetcodeProblems/Algorithms/easy/Maximun_Subarray").maxSubArray;
 
 function test() {
   assert.equal(maxSubArray([]), 0);
diff --git a/LeetcodeProblemsTests/Algorithms/Min_Stack_Test.js b/LeetcodeProblemsTests/Algorithms/easy/Min_Stack_Test.js
similarity index 78%
rename from LeetcodeProblemsTests/Algorithms/Min_Stack_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/Min_Stack_Test.js
index 5cbddda..d94fb53 100644
--- a/LeetcodeProblemsTests/Algorithms/Min_Stack_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/easy/Min_Stack_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const MinStack = require("../../LeetcodeProblems/Algorithms/Min_Stack").MinStack;
+const MinStack = require("../../../LeetcodeProblems/Algorithms/easy/Min_Stack").MinStack;
 
 function test() {
   var minStack = new MinStack();
diff --git a/LeetcodeProblemsTests/Algorithms/Number_of_Segments_in_a_String_Test.js b/LeetcodeProblemsTests/Algorithms/easy/Number_of_Segments_in_a_String_Test.js
similarity index 74%
rename from LeetcodeProblemsTests/Algorithms/Number_of_Segments_in_a_String_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/Number_of_Segments_in_a_String_Test.js
index 13a982f..a33787f 100644
--- a/LeetcodeProblemsTests/Algorithms/Number_of_Segments_in_a_String_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/easy/Number_of_Segments_in_a_String_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const countSegments = require("../../LeetcodeProblems/Algorithms/Number_of_Segments_in_a_String").countSegments;
+const countSegments = require("../../../LeetcodeProblems/Algorithms/easy/Number_of_Segments_in_a_String").countSegments;
 
 function test() {
   assert.equal(countSegments(" "), 0);
diff --git a/LeetcodeProblemsTests/Algorithms/Reverse_String_II_Test.js b/LeetcodeProblemsTests/Algorithms/easy/Reverse_String_II_Test.js
similarity index 74%
rename from LeetcodeProblemsTests/Algorithms/Reverse_String_II_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/Reverse_String_II_Test.js
index 9fae9d4..897f97f 100644
--- a/LeetcodeProblemsTests/Algorithms/Reverse_String_II_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/easy/Reverse_String_II_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const reverseStr = require("../../LeetcodeProblems/Algorithms/Reverse_String_II").reverseStr;
+const reverseStr = require("../../../LeetcodeProblems/Algorithms/easy/Reverse_String_II").reverseStr;
 
 var test = function() {
   assert.equal(reverseStr("abcdefg", 2), "bacdfeg");
diff --git a/LeetcodeProblemsTests/Algorithms/Same_Tree_Test.js b/LeetcodeProblemsTests/Algorithms/easy/Same_Tree_Test.js
similarity index 100%
rename from LeetcodeProblemsTests/Algorithms/Same_Tree_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/Same_Tree_Test.js
diff --git a/LeetcodeProblemsTests/Algorithms/Shuffle_String_Test.js b/LeetcodeProblemsTests/Algorithms/easy/Shuffle_String_Test.js
similarity index 74%
rename from LeetcodeProblemsTests/Algorithms/Shuffle_String_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/Shuffle_String_Test.js
index cb37d91..8ca038b 100644
--- a/LeetcodeProblemsTests/Algorithms/Shuffle_String_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/easy/Shuffle_String_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const restoreString = require("../../LeetcodeProblems/Algorithms/Shuffle_String").restoreString;
+const restoreString = require("../../../LeetcodeProblems/Algorithms/easy/Shuffle_String").restoreString;
 
 var test = function () {
   assert.equal(restoreString("codeleet",[4,5,6,7,0,2,1,3]),"leetcode");
diff --git a/LeetcodeProblemsTests/Algorithms/Sum_Of_Square_Numbers_Test.js b/LeetcodeProblemsTests/Algorithms/easy/Sum_Of_Square_Numbers_Test.js
similarity index 76%
rename from LeetcodeProblemsTests/Algorithms/Sum_Of_Square_Numbers_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/Sum_Of_Square_Numbers_Test.js
index 26c033a..1a93b94 100644
--- a/LeetcodeProblemsTests/Algorithms/Sum_Of_Square_Numbers_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/easy/Sum_Of_Square_Numbers_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const judgeSquareSum = require("../../LeetcodeProblems/Algorithms/Sum_Of_Square_Numbers").judgeSquareSum;
+const judgeSquareSum = require("../../../LeetcodeProblems/Algorithms/easy/Sum_Of_Square_Numbers").judgeSquareSum;
 
 var test = function() {
   assert.strictEqual(judgeSquareSum(0), true);
diff --git a/LeetcodeProblemsTests/Algorithms/Symmetric_Tree_Test.js b/LeetcodeProblemsTests/Algorithms/easy/Symmetric_Tree_Test.js
similarity index 100%
rename from LeetcodeProblemsTests/Algorithms/Symmetric_Tree_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/Symmetric_Tree_Test.js
diff --git a/LeetcodeProblemsTests/Algorithms/Tic_Tac_Toe_Test.js b/LeetcodeProblemsTests/Algorithms/easy/Tic_Tac_Toe_Test.js
similarity index 81%
rename from LeetcodeProblemsTests/Algorithms/Tic_Tac_Toe_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/Tic_Tac_Toe_Test.js
index d1d98ec..a9ae9e3 100644
--- a/LeetcodeProblemsTests/Algorithms/Tic_Tac_Toe_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/easy/Tic_Tac_Toe_Test.js
@@ -1,4 +1,4 @@
-const TicTacToe = require("../../LeetcodeProblems/Algorithms/Tic_Tac_Toe").TicTacToe;
+const TicTacToe = require("../../../LeetcodeProblems/Algorithms/easy/Tic_Tac_Toe").TicTacToe;
 
 var test = function() {
   let ticTacToe = new TicTacToe();
diff --git a/LeetcodeProblemsTests/Algorithms/Valid_Parentheses_Test.js b/LeetcodeProblemsTests/Algorithms/easy/Valid_Parentheses_Test.js
similarity index 77%
rename from LeetcodeProblemsTests/Algorithms/Valid_Parentheses_Test.js
rename to LeetcodeProblemsTests/Algorithms/easy/Valid_Parentheses_Test.js
index a110c7b..499a6ba 100644
--- a/LeetcodeProblemsTests/Algorithms/Valid_Parentheses_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/easy/Valid_Parentheses_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const isValid = require("../../LeetcodeProblems/Algorithms/Valid_Parentheses").isValid;
+const isValid = require("../../../LeetcodeProblems/Algorithms/easy/Valid_Parentheses").isValid;
 
 var test = function () {
   assert.strictEqual(isValid(""), true);
diff --git a/LeetcodeProblemsTests/Algorithms/Edit_Distance_Test.js b/LeetcodeProblemsTests/Algorithms/hard/Edit_Distance_Test.js
similarity index 60%
rename from LeetcodeProblemsTests/Algorithms/Edit_Distance_Test.js
rename to LeetcodeProblemsTests/Algorithms/hard/Edit_Distance_Test.js
index 2810420..46732ca 100644
--- a/LeetcodeProblemsTests/Algorithms/Edit_Distance_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/hard/Edit_Distance_Test.js
@@ -1,6 +1,6 @@
 const assert = require("assert");
-var minDistance = require("../../LeetcodeProblems/Algorithms/Edit_Distance").minDistance;
-var minDistance2 = require("../../LeetcodeProblems/Algorithms/Edit_Distance").minDistance2;
+var minDistance = require("../../../LeetcodeProblems/Algorithms/hard/Edit_Distance").minDistance;
+var minDistance2 = require("../../../LeetcodeProblems/Algorithms/hard/Edit_Distance").minDistance2;
 
 function test() {
   assert.equal(minDistance("ros", "horse"), 3);
diff --git a/LeetcodeProblemsTests/Algorithms/Longest_Consecutive_Sequence_Test.js b/LeetcodeProblemsTests/Algorithms/hard/Longest_Consecutive_Sequence_Test.js
similarity index 74%
rename from LeetcodeProblemsTests/Algorithms/Longest_Consecutive_Sequence_Test.js
rename to LeetcodeProblemsTests/Algorithms/hard/Longest_Consecutive_Sequence_Test.js
index 00cc6ed..96c2bf8 100644
--- a/LeetcodeProblemsTests/Algorithms/Longest_Consecutive_Sequence_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/hard/Longest_Consecutive_Sequence_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const longestConsecutive = require("../../LeetcodeProblems/Algorithms/Longest_Consecutive_Sequence").longestConsecutive;
+const longestConsecutive = require("../../../LeetcodeProblems/Algorithms/hard/Longest_Consecutive_Sequence").longestConsecutive;
 
 function test() {
   assert.equal(longestConsecutive([100, 1, 200, 3, 2, 400, 201]), 3);
diff --git a/LeetcodeProblemsTests/Algorithms/Minimum_Window_Substring_Test.js b/LeetcodeProblemsTests/Algorithms/hard/Minimum_Window_Substring_Test.js
similarity index 77%
rename from LeetcodeProblemsTests/Algorithms/Minimum_Window_Substring_Test.js
rename to LeetcodeProblemsTests/Algorithms/hard/Minimum_Window_Substring_Test.js
index e580710..452aacf 100644
--- a/LeetcodeProblemsTests/Algorithms/Minimum_Window_Substring_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/hard/Minimum_Window_Substring_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const minWindow = require("../../LeetcodeProblems/Algorithms/Minimum_Window_Substring").minWindow;
+const minWindow = require("../../../LeetcodeProblems/Algorithms/hard/Minimum_Window_Substring").minWindow;
 
 function test() {
   assert.equal(minWindow("ADOBECODEBANC", "ABC"), "BANC");
diff --git a/LeetcodeProblemsTests/Algorithms/NQueens_Test.js b/LeetcodeProblemsTests/Algorithms/hard/NQueens_Test.js
similarity index 86%
rename from LeetcodeProblemsTests/Algorithms/NQueens_Test.js
rename to LeetcodeProblemsTests/Algorithms/hard/NQueens_Test.js
index 42d95ff..18ed528 100644
--- a/LeetcodeProblemsTests/Algorithms/NQueens_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/hard/NQueens_Test.js
@@ -1,5 +1,5 @@
 // const assert = require("assert");
-const solveNQueens = require("../../LeetcodeProblems/Algorithms/NQueens").solveNQueens;
+const solveNQueens = require("../../../LeetcodeProblems/Algorithms/hard/NQueens").solveNQueens;
 
 // TODO: Add assertions
 
diff --git a/LeetcodeProblemsTests/Algorithms/Regular_Expression_Matching_Test.js b/LeetcodeProblemsTests/Algorithms/hard/Regular_Expression_Matching_Test.js
similarity index 77%
rename from LeetcodeProblemsTests/Algorithms/Regular_Expression_Matching_Test.js
rename to LeetcodeProblemsTests/Algorithms/hard/Regular_Expression_Matching_Test.js
index 95bca74..c8ee882 100644
--- a/LeetcodeProblemsTests/Algorithms/Regular_Expression_Matching_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/hard/Regular_Expression_Matching_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const isMatch = require("../../LeetcodeProblems/Algorithms/Regular_Expression_Matching").isMatch;
+const isMatch = require("../../../LeetcodeProblems/Algorithms/hard/Regular_Expression_Matching").isMatch;
 
 var test = function() {
   assert.equal(isMatch("aa", "a"), false);
diff --git a/LeetcodeProblemsTests/Algorithms/Remove_Invalid_Parentheses_Test.js b/LeetcodeProblemsTests/Algorithms/hard/Remove_Invalid_Parentheses_Test.js
similarity index 69%
rename from LeetcodeProblemsTests/Algorithms/Remove_Invalid_Parentheses_Test.js
rename to LeetcodeProblemsTests/Algorithms/hard/Remove_Invalid_Parentheses_Test.js
index d345205..6b8f995 100644
--- a/LeetcodeProblemsTests/Algorithms/Remove_Invalid_Parentheses_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/hard/Remove_Invalid_Parentheses_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const removeInvalidParentheses = require("../../LeetcodeProblems/Algorithms/Remove_Invalid_Parentheses").removeInvalidParentheses;
+const removeInvalidParentheses = require("../../../LeetcodeProblems/Algorithms/hard/Remove_Invalid_Parentheses").removeInvalidParentheses;
 
 var test = function() {
   assert.equal(removeInvalidParentheses("))))(()"), "()");
diff --git a/LeetcodeProblemsTests/Algorithms/Set_Matrix_Zeroes_Test.js b/LeetcodeProblemsTests/Algorithms/hard/Set_Matrix_Zeroes_Test.js
similarity index 66%
rename from LeetcodeProblemsTests/Algorithms/Set_Matrix_Zeroes_Test.js
rename to LeetcodeProblemsTests/Algorithms/hard/Set_Matrix_Zeroes_Test.js
index 98709fe..39b9e87 100644
--- a/LeetcodeProblemsTests/Algorithms/Set_Matrix_Zeroes_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/hard/Set_Matrix_Zeroes_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const setZeroes = require("../../LeetcodeProblems/Algorithms/Set_Matrix_Zeroes").setZeroes;
+const setZeroes = require("../../../LeetcodeProblems/Algorithms/hard/Set_Matrix_Zeroes").setZeroes;
 
 var test = function() {
   assert.deepEqual(
diff --git a/LeetcodeProblemsTests/Algorithms/merge_k_sorted_lists_Test.js b/LeetcodeProblemsTests/Algorithms/hard/merge_k_sorted_lists_Test.js
similarity index 68%
rename from LeetcodeProblemsTests/Algorithms/merge_k_sorted_lists_Test.js
rename to LeetcodeProblemsTests/Algorithms/hard/merge_k_sorted_lists_Test.js
index 0db1c51..ba1051e 100644
--- a/LeetcodeProblemsTests/Algorithms/merge_k_sorted_lists_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/hard/merge_k_sorted_lists_Test.js
@@ -1,7 +1,7 @@
 const assert = require("assert");
-const ListNodeTestHelper = require("../../UtilsClasses/ListNodeTestHelper");
-var ListNode = require("../../UtilsClasses/ListNode").ListNode;
-const mergeKLists = require("../../LeetcodeProblems/Algorithms/merge_k_sorted_lists").mergeKLists;
+const ListNodeTestHelper = require("../../../UtilsClasses/ListNodeTestHelper");
+var ListNode = require("../../../UtilsClasses/ListNode").ListNode;
+const mergeKLists = require("../../../LeetcodeProblems/Algorithms/hard/merge_k_sorted_lists").mergeKLists;
 
 function test() {
   assert.deepEqual(mergeKLists([]), null);
diff --git a/LeetcodeProblemsTests/Algorithms/3Sum_Closest_Test.js b/LeetcodeProblemsTests/Algorithms/medium/3Sum_Closest_Test.js
similarity index 71%
rename from LeetcodeProblemsTests/Algorithms/3Sum_Closest_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/3Sum_Closest_Test.js
index 5d397ad..a0f109c 100644
--- a/LeetcodeProblemsTests/Algorithms/3Sum_Closest_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/3Sum_Closest_Test.js
@@ -1,6 +1,6 @@
 const assert = require("assert");
 const threeSumClosest =
-  require("../../LeetcodeProblems/Algorithms/3SumClosest").threeSumClosest;
+  require("../../../LeetcodeProblems/Algorithms/medium/3SumClosest").threeSumClosest;
 
 var test = function () {
   assert.equal(2, threeSumClosest([-1, 2, 1, -4], 1));
diff --git a/LeetcodeProblemsTests/Algorithms/3Sum_Test.js b/LeetcodeProblemsTests/Algorithms/medium/3Sum_Test.js
similarity index 84%
rename from LeetcodeProblemsTests/Algorithms/3Sum_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/3Sum_Test.js
index 4dd352c..445c40b 100644
--- a/LeetcodeProblemsTests/Algorithms/3Sum_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/3Sum_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const threeSum = require("../../LeetcodeProblems/Algorithms/3Sum").threeSum;
+const threeSum = require("../../../LeetcodeProblems/Algorithms/medium/3Sum").threeSum;
 
 var test = function () {
   assert.deepEqual(threeSum([]), []);
diff --git a/LeetcodeProblemsTests/Algorithms/Add_Two_Numbers_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Add_Two_Numbers_Test.js
similarity index 69%
rename from LeetcodeProblemsTests/Algorithms/Add_Two_Numbers_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Add_Two_Numbers_Test.js
index 5af6f69..9675a65 100644
--- a/LeetcodeProblemsTests/Algorithms/Add_Two_Numbers_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Add_Two_Numbers_Test.js
@@ -1,6 +1,6 @@
-const addTwoNumbers = require("../../LeetcodeProblems/Algorithms/Add_Two_Numbers").addTwoNumbers;
-const ListNodeTestHelper = require("../../UtilsClasses/ListNodeTestHelper");
-var ListNode = require("../../UtilsClasses/ListNode").ListNode;
+const addTwoNumbers = require("../../../LeetcodeProblems/Algorithms/medium/Add_Two_Numbers").addTwoNumbers;
+const ListNodeTestHelper = require("../../../UtilsClasses/ListNodeTestHelper");
+var ListNode = require("../../../UtilsClasses/ListNode").ListNode;
 
 function test() {
   const list1 = ListNode.linkenList([1,2,3,4]);
diff --git a/LeetcodeProblemsTests/Algorithms/Best_Time_To_Buy_And_Sell_Stock_II_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Best_Time_To_Buy_And_Sell_Stock_II_Test.js
similarity index 60%
rename from LeetcodeProblemsTests/Algorithms/Best_Time_To_Buy_And_Sell_Stock_II_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Best_Time_To_Buy_And_Sell_Stock_II_Test.js
index c3207fb..7a2561c 100644
--- a/LeetcodeProblemsTests/Algorithms/Best_Time_To_Buy_And_Sell_Stock_II_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Best_Time_To_Buy_And_Sell_Stock_II_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const maxProfit = require("../../LeetcodeProblems/Algorithms/Best_Time_To_Buy_And_Sell_Stock_II").maxProfit;
+const maxProfit = require("../../../LeetcodeProblems/Algorithms/medium/Best_Time_To_Buy_And_Sell_Stock_II").maxProfit;
 
 function test() {
   assert.equal(maxProfit([7,1,5,3,6,4]), 7);
diff --git a/LeetcodeProblemsTests/Algorithms/Clone_Graph_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Clone_Graph_Test.js
similarity index 100%
rename from LeetcodeProblemsTests/Algorithms/Clone_Graph_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Clone_Graph_Test.js
diff --git a/LeetcodeProblemsTests/Algorithms/Coin_Change_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Coin_Change_Test.js
similarity index 78%
rename from LeetcodeProblemsTests/Algorithms/Coin_Change_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Coin_Change_Test.js
index df5ae45..9bd9a50 100644
--- a/LeetcodeProblemsTests/Algorithms/Coin_Change_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Coin_Change_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const coinChange = require("../../LeetcodeProblems/Algorithms/Coin_Change").coinChange;
+const coinChange = require("../../../LeetcodeProblems/Algorithms/medium/Coin_Change").coinChange;
 
 function test() {
   assert.equal(coinChange([], 3), -1);
diff --git a/LeetcodeProblemsTests/Algorithms/Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal_Test.js
similarity index 52%
rename from LeetcodeProblemsTests/Algorithms/Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal_Test.js
index 1ddea51..793d6fd 100644
--- a/LeetcodeProblemsTests/Algorithms/Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal_Test.js
@@ -1,5 +1,5 @@
 // const assert = require("assert");
-var buildTree = require("../../LeetcodeProblems/Algorithms/Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal").buildTree;
+var buildTree = require("../../../LeetcodeProblems/Algorithms/medium/Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal").buildTree;
 
 function test() {
   // TODO
diff --git a/LeetcodeProblemsTests/Algorithms/Container_With_Most_Water_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Container_With_Most_Water_Test.js
similarity index 61%
rename from LeetcodeProblemsTests/Algorithms/Container_With_Most_Water_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Container_With_Most_Water_Test.js
index cb08735..7d52f78 100644
--- a/LeetcodeProblemsTests/Algorithms/Container_With_Most_Water_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Container_With_Most_Water_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const maxArea = require("../../LeetcodeProblems/Algorithms/Container_With_Most_Water").maxArea;
+const maxArea = require("../../../LeetcodeProblems/Algorithms/medium/Container_With_Most_Water").maxArea;
 
 function test() {
   assert.equal(49, maxArea([1,8,6,2,5,4,8,3,7]));
diff --git a/LeetcodeProblemsTests/Algorithms/Design_Circular_Deque_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Design_Circular_Deque_Test.js
similarity index 80%
rename from LeetcodeProblemsTests/Algorithms/Design_Circular_Deque_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Design_Circular_Deque_Test.js
index cf8bc81..5a3ddd2 100644
--- a/LeetcodeProblemsTests/Algorithms/Design_Circular_Deque_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Design_Circular_Deque_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-var MyCircularDeque = require("../../LeetcodeProblems/Algorithms/Design_Circular_Deque").MyCircularDeque;
+var MyCircularDeque = require("../../../LeetcodeProblems/Algorithms/medium/Design_Circular_Deque").MyCircularDeque;
 
 var test =  function() {
   const obj = new MyCircularDeque(3);
diff --git a/LeetcodeProblemsTests/Algorithms/Escape_The_Ghosts_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Escape_The_Ghosts_Test.js
similarity index 70%
rename from LeetcodeProblemsTests/Algorithms/Escape_The_Ghosts_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Escape_The_Ghosts_Test.js
index 4225fbf..8ce944c 100644
--- a/LeetcodeProblemsTests/Algorithms/Escape_The_Ghosts_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Escape_The_Ghosts_Test.js
@@ -1,6 +1,6 @@
 
 const assert = require("assert");
-var escapeGhosts = require("../../LeetcodeProblems/Algorithms/Escape_The_Ghosts").escapeGhosts;
+var escapeGhosts = require("../../../LeetcodeProblems/Algorithms/medium/Escape_The_Ghosts").escapeGhosts;
 
 function test() {
   assert.equal(escapeGhosts([[1, 0], [0, 3]], [0, 1]), true);
diff --git a/LeetcodeProblemsTests/Algorithms/Find_Anagrams_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Find_Anagrams_Test.js
similarity index 75%
rename from LeetcodeProblemsTests/Algorithms/Find_Anagrams_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Find_Anagrams_Test.js
index 3b90a57..13de13a 100644
--- a/LeetcodeProblemsTests/Algorithms/Find_Anagrams_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Find_Anagrams_Test.js
@@ -1,6 +1,6 @@
 
 const assert = require("assert");
-var findAnagrams = require("../../LeetcodeProblems/Algorithms/Find_Anagrams").findAnagrams;
+var findAnagrams = require("../../../LeetcodeProblems/Algorithms/medium/Find_Anagrams").findAnagrams;
 
 function test() {
   assert.deepEqual([], findAnagrams("AA", "BB"));
diff --git a/LeetcodeProblemsTests/Algorithms/Find_Subarrays_With_Equal_Sum_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Find_Subarrays_With_Equal_Sum_Test.js
similarity index 65%
rename from LeetcodeProblemsTests/Algorithms/Find_Subarrays_With_Equal_Sum_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Find_Subarrays_With_Equal_Sum_Test.js
index 956a327..8a6ad5f 100644
--- a/LeetcodeProblemsTests/Algorithms/Find_Subarrays_With_Equal_Sum_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Find_Subarrays_With_Equal_Sum_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const findSubarrays = require("../../LeetcodeProblems/Algorithms/Find_Subarrays_With_Equal_Sum").findSubarrays;
+const findSubarrays = require("../../../LeetcodeProblems/Algorithms/medium/Find_Subarrays_With_Equal_Sum").findSubarrays;
 
 var test = function () {
   assert.equal(findSubarrays([4,2,4]), true);
diff --git a/LeetcodeProblemsTests/Algorithms/Gas_Station_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Gas_Station_Test.js
similarity index 70%
rename from LeetcodeProblemsTests/Algorithms/Gas_Station_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Gas_Station_Test.js
index ef35fe6..ebee7ad 100644
--- a/LeetcodeProblemsTests/Algorithms/Gas_Station_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Gas_Station_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const canCompleteCircuit = require("../../LeetcodeProblems/Algorithms/Gas_Station").canCompleteCircuit;
+const canCompleteCircuit = require("../../../LeetcodeProblems/Algorithms/medium/Gas_Station").canCompleteCircuit;
 
 function test() {
   assert.equal(3, canCompleteCircuit([1,2,3,4,5], [3,4,5,1,2]));
diff --git a/LeetcodeProblemsTests/Algorithms/Generate_Parenthesis_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Generate_Parenthesis_Test.js
similarity index 100%
rename from LeetcodeProblemsTests/Algorithms/Generate_Parenthesis_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Generate_Parenthesis_Test.js
diff --git a/LeetcodeProblemsTests/Algorithms/Group_Anagrams_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Group_Anagrams_Test.js
similarity index 68%
rename from LeetcodeProblemsTests/Algorithms/Group_Anagrams_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Group_Anagrams_Test.js
index c871e7e..1588606 100644
--- a/LeetcodeProblemsTests/Algorithms/Group_Anagrams_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Group_Anagrams_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const groupAnagrams = require("../../LeetcodeProblems/Algorithms/Group_Anagrams").groupAnagrams;
+const groupAnagrams = require("../../../LeetcodeProblems/Algorithms/medium/Group_Anagrams").groupAnagrams;
 
 function test() {
   assert.deepEqual(
diff --git a/LeetcodeProblemsTests/Algorithms/K_Closest_Points_to_Origin_Test.js b/LeetcodeProblemsTests/Algorithms/medium/K_Closest_Points_to_Origin_Test.js
similarity index 54%
rename from LeetcodeProblemsTests/Algorithms/K_Closest_Points_to_Origin_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/K_Closest_Points_to_Origin_Test.js
index 3164742..24a6f0e 100644
--- a/LeetcodeProblemsTests/Algorithms/K_Closest_Points_to_Origin_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/K_Closest_Points_to_Origin_Test.js
@@ -1,16 +1,17 @@
 const assert = require("assert");
-var kClosest = require("../../LeetcodeProblems/Algorithms/K_Closest_Points_to_Origin").kClosest;
+var kClosest = require("../../../LeetcodeProblems/Algorithms/medium/K_Closest_Points_to_Origin").kClosest;
 
 function test1() {
   var points = [[1,3],[-2,2]];
   var output = [[-2,2]];
-  assert.strictEqual(kClosest(points,1), output);
+  assert.deepStrictEqual(kClosest(points,1), output);
 }
 
 function test2() {
   var points = [[3,3],[5,-1],[-2,4]];
   var output = [[-2,4],[3,3]];
-  assert.strictEqual(kClosest(points,2), output);
+
+  assert.deepStrictEqual(kClosest(points,2).sort, output.sort);
 }
 
 function test() {
diff --git a/LeetcodeProblemsTests/Algorithms/Kth_Largest_Element_in_an_Array_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Kth_Largest_Element_in_an_Array_Test.js
similarity index 69%
rename from LeetcodeProblemsTests/Algorithms/Kth_Largest_Element_in_an_Array_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Kth_Largest_Element_in_an_Array_Test.js
index 156d2e1..94ff0a5 100644
--- a/LeetcodeProblemsTests/Algorithms/Kth_Largest_Element_in_an_Array_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Kth_Largest_Element_in_an_Array_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const findKthLargest = require("../../LeetcodeProblems/Algorithms/Kth_Largest_Element_in_an_Array").findKthLargest;
+const findKthLargest = require("../../../LeetcodeProblems/Algorithms/medium/Kth_Largest_Element_in_an_Array").findKthLargest;
 
 function test() {
   assert.equal(findKthLargest([3,2,1,5,6,4], 2), 5);
diff --git a/LeetcodeProblemsTests/Algorithms/Linked_List_Cycle_II_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Linked_List_Cycle_II_Test.js
similarity index 77%
rename from LeetcodeProblemsTests/Algorithms/Linked_List_Cycle_II_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Linked_List_Cycle_II_Test.js
index 5014106..665843d 100644
--- a/LeetcodeProblemsTests/Algorithms/Linked_List_Cycle_II_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Linked_List_Cycle_II_Test.js
@@ -1,6 +1,6 @@
 const assert = require("assert");
-var ListNode = require("../../UtilsClasses/ListNode").ListNode;
-const detectCycle = require("../../LeetcodeProblems/Algorithms/Linked_List_Cycle_II").detectCycle;
+var ListNode = require("../../../UtilsClasses/ListNode").ListNode;
+const detectCycle = require("../../../LeetcodeProblems/Algorithms/medium/Linked_List_Cycle_II").detectCycle;
 
 var test = function() {
   const cycle = buildCycle();
diff --git a/LeetcodeProblemsTests/Algorithms/Longest_Palindromic_Substring_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Longest_Palindromic_Substring_Test.js
similarity index 75%
rename from LeetcodeProblemsTests/Algorithms/Longest_Palindromic_Substring_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Longest_Palindromic_Substring_Test.js
index cab1b1b..863a459 100644
--- a/LeetcodeProblemsTests/Algorithms/Longest_Palindromic_Substring_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Longest_Palindromic_Substring_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const longestPalindrome = require("../../LeetcodeProblems/Algorithms/Longest_Palindromic_Substring").longestPalindrome;
+const longestPalindrome = require("../../../LeetcodeProblems/Algorithms/medium/Longest_Palindromic_Substring").longestPalindrome;
 
 function test() {
   assert.equal(longestPalindrome("pabcdcbte"), "bcdcb");
diff --git a/LeetcodeProblemsTests/Algorithms/Longest_Substring_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Longest_Substring_Test.js
similarity index 72%
rename from LeetcodeProblemsTests/Algorithms/Longest_Substring_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Longest_Substring_Test.js
index f4a873e..1595415 100644
--- a/LeetcodeProblemsTests/Algorithms/Longest_Substring_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Longest_Substring_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const lengthOfLongestSubstring = require("../../LeetcodeProblems/Algorithms/Longest_Substring").lengthOfLongestSubstring;
+const lengthOfLongestSubstring = require("../../../LeetcodeProblems/Algorithms/medium/Longest_Substring").lengthOfLongestSubstring;
 
 function test() {
   assert.equal(4, lengthOfLongestSubstring("abcdbcd"));
diff --git a/LeetcodeProblemsTests/Algorithms/Lowest_Common_Ancestor_of_a_Binary_Tree_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Lowest_Common_Ancestor_of_a_Binary_Tree_Test.js
similarity index 71%
rename from LeetcodeProblemsTests/Algorithms/Lowest_Common_Ancestor_of_a_Binary_Tree_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Lowest_Common_Ancestor_of_a_Binary_Tree_Test.js
index 045f9ba..af6d8ff 100644
--- a/LeetcodeProblemsTests/Algorithms/Lowest_Common_Ancestor_of_a_Binary_Tree_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Lowest_Common_Ancestor_of_a_Binary_Tree_Test.js
@@ -1,7 +1,7 @@
 // const assert = require("assert");
-var TreeNode = require("../../UtilsClasses/TreeNode").TreeNode;
-const lowestCommonAncestor = require("../../LeetcodeProblems/Algorithms/Lowest_Common_Ancestor_of_a_Binary_Tree").lowestCommonAncestor;
-const lowestCommonAncestor2 = require("../../LeetcodeProblems/Algorithms/Lowest_Common_Ancestor_of_a_Binary_Tree").lowestCommonAncestor2;
+var TreeNode = require("../../../UtilsClasses/TreeNode").TreeNode;
+const lowestCommonAncestor = require("../../../LeetcodeProblems/Algorithms/medium/Lowest_Common_Ancestor_of_a_Binary_Tree").lowestCommonAncestor;
+const lowestCommonAncestor2 = require("../../../LeetcodeProblems/Algorithms/medium/Lowest_Common_Ancestor_of_a_Binary_Tree").lowestCommonAncestor2;
 
 var test = function() {
   var root = new TreeNode(3);
diff --git a/LeetcodeProblemsTests/Algorithms/Max_Area_Of_Island_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Max_Area_Of_Island_Test.js
similarity index 89%
rename from LeetcodeProblemsTests/Algorithms/Max_Area_Of_Island_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Max_Area_Of_Island_Test.js
index b8269e6..28e8f34 100644
--- a/LeetcodeProblemsTests/Algorithms/Max_Area_Of_Island_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Max_Area_Of_Island_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const { maxAreaOfIsland } = require("../../LeetcodeProblems/Algorithms/Max_Area_Of_Island");
+const { maxAreaOfIsland } = require("../../../LeetcodeProblems/Algorithms/medium/Max_Area_Of_Island");
 
 function test1() {
   var matrix = [
diff --git a/LeetcodeProblemsTests/Algorithms/Max_Consecutive_Ones_III_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Max_Consecutive_Ones_III_Test.js
similarity index 75%
rename from LeetcodeProblemsTests/Algorithms/Max_Consecutive_Ones_III_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Max_Consecutive_Ones_III_Test.js
index ef4eb81..3314c85 100644
--- a/LeetcodeProblemsTests/Algorithms/Max_Consecutive_Ones_III_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Max_Consecutive_Ones_III_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const longestOnes = require("../../LeetcodeProblems/Algorithms/Max_Consecutive_Ones_III").longestOnes;
+const longestOnes = require("../../../LeetcodeProblems/Algorithms/medium/Max_Consecutive_Ones_III").longestOnes;
 
 function test() {
   assert.equal(1, longestOnes([1], 1));
diff --git a/LeetcodeProblemsTests/Algorithms/Maximal_Square_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Maximal_Square_Test.js
similarity index 76%
rename from LeetcodeProblemsTests/Algorithms/Maximal_Square_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Maximal_Square_Test.js
index 11a0764..b29b21b 100644
--- a/LeetcodeProblemsTests/Algorithms/Maximal_Square_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Maximal_Square_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const maximalSquare = require("../../LeetcodeProblems/Algorithms/Maximal_Square").maximalSquare;
+const maximalSquare = require("../../../LeetcodeProblems/Algorithms/medium/Maximal_Square").maximalSquare;
 
 function test() {
   assert.equal(maximalSquare([["1","0"]]), 1);
diff --git a/LeetcodeProblemsTests/Algorithms/Maximise_Hour_Glass_Sum.js b/LeetcodeProblemsTests/Algorithms/medium/Maximise_Hour_Glass_Sum.js
similarity index 67%
rename from LeetcodeProblemsTests/Algorithms/Maximise_Hour_Glass_Sum.js
rename to LeetcodeProblemsTests/Algorithms/medium/Maximise_Hour_Glass_Sum.js
index f728cfd..f3f2cf2 100644
--- a/LeetcodeProblemsTests/Algorithms/Maximise_Hour_Glass_Sum.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Maximise_Hour_Glass_Sum.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const maxSum = require("../../LeetcodeProblems/Algorithms/Maximise_Hour_Glass_Sum").maxSum;
+const maxSum = require("../../../LeetcodeProblems/Algorithms/medium/Maximise_Hour_Glass_Sum").maxSum;
 
 function test() {
   assert.equal(maxSum([[6,2,1,3],[4,2,1,5],[9,2,8,7],[4,1,2,9]]), 30);
diff --git a/LeetcodeProblemsTests/Algorithms/Minimize_Maximum_Pair_Sum_In_Array_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Minimize_Maximum_Pair_Sum_In_Array_Test.js
similarity index 64%
rename from LeetcodeProblemsTests/Algorithms/Minimize_Maximum_Pair_Sum_In_Array_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Minimize_Maximum_Pair_Sum_In_Array_Test.js
index 3180536..1842614 100644
--- a/LeetcodeProblemsTests/Algorithms/Minimize_Maximum_Pair_Sum_In_Array_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Minimize_Maximum_Pair_Sum_In_Array_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const minPairSum = require("../../LeetcodeProblems/Algorithms/Minimize_Maximum_Pair_Sum_In_Array").minPairSum;
+const minPairSum = require("../../../LeetcodeProblems/Algorithms/medium/Minimize_Maximum_Pair_Sum_In_Array").minPairSum;
 
 var test = function () {
   assert.equal(minPairSum([3,5,2,3]), 7);
diff --git a/LeetcodeProblemsTests/Algorithms/Minimum_Add_To_Make_Parentheses_Valid_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Minimum_Add_To_Make_Parentheses_Valid_Test.js
similarity index 73%
rename from LeetcodeProblemsTests/Algorithms/Minimum_Add_To_Make_Parentheses_Valid_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Minimum_Add_To_Make_Parentheses_Valid_Test.js
index 69baf4d..9c75aa4 100644
--- a/LeetcodeProblemsTests/Algorithms/Minimum_Add_To_Make_Parentheses_Valid_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Minimum_Add_To_Make_Parentheses_Valid_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const minAddToMakeValid = require("../../LeetcodeProblems/Algorithms/Minimum_Add_To_Make_Parentheses_Valid").minAddToMakeValid;
+const minAddToMakeValid = require("../../../LeetcodeProblems/Algorithms/medium/Minimum_Add_To_Make_Parentheses_Valid").minAddToMakeValid;
 
 var test = function() {
   assert.strictEqual(1, minAddToMakeValid("()("));
diff --git a/LeetcodeProblemsTests/Algorithms/Minimum_Size_Subarray_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Minimum_Size_Subarray_Test.js
similarity index 80%
rename from LeetcodeProblemsTests/Algorithms/Minimum_Size_Subarray_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Minimum_Size_Subarray_Test.js
index a09502e..c5f8628 100644
--- a/LeetcodeProblemsTests/Algorithms/Minimum_Size_Subarray_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Minimum_Size_Subarray_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const minSubArrayLength = require("../../LeetcodeProblems/Algorithms/Minimum_Size_Subarray").minSubArrayLength;
+const minSubArrayLength = require("../../../LeetcodeProblems/Algorithms/medium/Minimum_Size_Subarray").minSubArrayLength;
 
 function test() {
   assert.equal(0, minSubArrayLength(10, []));
diff --git a/LeetcodeProblemsTests/Algorithms/Next_Permutation_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Next_Permutation_Test.js
similarity index 75%
rename from LeetcodeProblemsTests/Algorithms/Next_Permutation_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Next_Permutation_Test.js
index ec47f8c..f892f38 100644
--- a/LeetcodeProblemsTests/Algorithms/Next_Permutation_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Next_Permutation_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const nextPermutation = require("../../LeetcodeProblems/Algorithms/Next_Permutation").nextPermutation;
+const nextPermutation = require("../../../LeetcodeProblems/Algorithms/medium/Next_Permutation").nextPermutation;
 
 function test() {
   let test1 = [1,2,3];
diff --git a/LeetcodeProblemsTests/Algorithms/Number_of_Islands_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Number_of_Islands_Test.js
similarity index 75%
rename from LeetcodeProblemsTests/Algorithms/Number_of_Islands_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Number_of_Islands_Test.js
index 1a46197..f3ef5e6 100644
--- a/LeetcodeProblemsTests/Algorithms/Number_of_Islands_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Number_of_Islands_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const numIslands = require("../../LeetcodeProblems/Algorithms/Number_of_Islands").numIslands;
+const numIslands = require("../../../LeetcodeProblems/Algorithms/medium/Number_of_Islands").numIslands;
 
 function test() {
   assert.equal(numIslands([[1]]), 1);
diff --git a/LeetcodeProblemsTests/Algorithms/Permutations_II_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Permutations_II_Test.js
similarity index 87%
rename from LeetcodeProblemsTests/Algorithms/Permutations_II_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Permutations_II_Test.js
index e464f80..20d1702 100644
--- a/LeetcodeProblemsTests/Algorithms/Permutations_II_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Permutations_II_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const permuteUnique = require("../../LeetcodeProblems/Algorithms/Permutations_II").permuteUnique;
+const permuteUnique = require("../../../LeetcodeProblems/Algorithms/medium/Permutations_II").permuteUnique;
 
 function test() {
   assert.deepEqual(
diff --git a/LeetcodeProblemsTests/Algorithms/Permutations_In_String_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Permutations_In_String_Test.js
similarity index 72%
rename from LeetcodeProblemsTests/Algorithms/Permutations_In_String_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Permutations_In_String_Test.js
index f8d4536..975bda8 100644
--- a/LeetcodeProblemsTests/Algorithms/Permutations_In_String_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Permutations_In_String_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const checkInclusion = require("../../LeetcodeProblems/Algorithms/Permutations_In_String").checkInclusion;
+const checkInclusion = require("../../../LeetcodeProblems/Algorithms/medium/Permutations_In_String").checkInclusion;
 
 function test() {
   assert.equal(false, checkInclusion("abc", "ab"));
diff --git a/LeetcodeProblemsTests/Algorithms/Permutations_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Permutations_Test.js
similarity index 78%
rename from LeetcodeProblemsTests/Algorithms/Permutations_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Permutations_Test.js
index f3f338e..1473732 100644
--- a/LeetcodeProblemsTests/Algorithms/Permutations_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Permutations_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const permute = require("../../LeetcodeProblems/Algorithms/Permutations").permute;
+const permute = require("../../../LeetcodeProblems/Algorithms/medium/Permutations").permute;
 
 function test() {
   assert.deepEqual(permute([]), [ [] ]);
diff --git a/LeetcodeProblemsTests/Algorithms/Permutations_With_Duplicates_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Permutations_With_Duplicates_Test.js
similarity index 75%
rename from LeetcodeProblemsTests/Algorithms/Permutations_With_Duplicates_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Permutations_With_Duplicates_Test.js
index 984192b..e355512 100644
--- a/LeetcodeProblemsTests/Algorithms/Permutations_With_Duplicates_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Permutations_With_Duplicates_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const subsetWithoutDuplicates = require("../../LeetcodeProblems/Algorithms/Permutations_With_Duplicates").subsetWithoutDuplicates;
+const subsetWithoutDuplicates = require("../../../LeetcodeProblems/Algorithms/medium/Permutations_With_Duplicates").subsetWithoutDuplicates;
 
 var test = function() {
   assert.deepEqual(
diff --git a/LeetcodeProblemsTests/Algorithms/Permutations_Without_Duplicates_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Permutations_Without_Duplicates_Test.js
similarity index 65%
rename from LeetcodeProblemsTests/Algorithms/Permutations_Without_Duplicates_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Permutations_Without_Duplicates_Test.js
index 379b627..a22e4e7 100644
--- a/LeetcodeProblemsTests/Algorithms/Permutations_Without_Duplicates_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Permutations_Without_Duplicates_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const subsetWithoutDuplicates = require("../../LeetcodeProblems/Algorithms/Permutations_Without_Duplicates").subsetWithoutDuplicates;
+const subsetWithoutDuplicates = require("../../../LeetcodeProblems/Algorithms/medium/Permutations_Without_Duplicates").subsetWithoutDuplicates;
 
 var test = function() {
   assert.deepEqual(
diff --git a/LeetcodeProblemsTests/Algorithms/Restore_IP_Addresses_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Restore_IP_Addresses_Test.js
similarity index 68%
rename from LeetcodeProblemsTests/Algorithms/Restore_IP_Addresses_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Restore_IP_Addresses_Test.js
index 9cf9ceb..17e2521 100644
--- a/LeetcodeProblemsTests/Algorithms/Restore_IP_Addresses_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Restore_IP_Addresses_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const restoreIpAddresses = require("../../LeetcodeProblems/Algorithms/Restore_IP_Addresses").restoreIpAddresses;
+const restoreIpAddresses = require("../../../LeetcodeProblems/Algorithms/medium/Restore_IP_Addresses").restoreIpAddresses;
 
 var test = function() {
   assert.deepEqual(restoreIpAddresses("010010"), [ "0.10.0.10", "0.100.1.0"]);
diff --git a/LeetcodeProblemsTests/Algorithms/Reverse_Integer_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Reverse_Integer_Test.js
similarity index 66%
rename from LeetcodeProblemsTests/Algorithms/Reverse_Integer_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Reverse_Integer_Test.js
index 95da676..627d72a 100644
--- a/LeetcodeProblemsTests/Algorithms/Reverse_Integer_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Reverse_Integer_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const reverseInteger = require("../../LeetcodeProblems/Algorithms/Reverse_Integer").reverseInteger;
+const reverseInteger = require("../../../LeetcodeProblems/Algorithms/medium/Reverse_Integer").reverseInteger;
 
 var test = function() {
   assert.equal(reverseInteger(123), 321);
diff --git a/LeetcodeProblemsTests/Algorithms/SearchIng_Rotated_Sorted_Array_Test.js b/LeetcodeProblemsTests/Algorithms/medium/SearchIng_Rotated_Sorted_Array_Test.js
similarity index 55%
rename from LeetcodeProblemsTests/Algorithms/SearchIng_Rotated_Sorted_Array_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/SearchIng_Rotated_Sorted_Array_Test.js
index 866496c..47bf614 100644
--- a/LeetcodeProblemsTests/Algorithms/SearchIng_Rotated_Sorted_Array_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/SearchIng_Rotated_Sorted_Array_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const search = require("../../LeetcodeProblems/Algorithms/SearchIng_Rotated_Sorted_Array").search;
+const search = require("../../../LeetcodeProblems/Algorithms/medium/SearchIng_Rotated_Sorted_Array").search;
 
 var test = function() {
   assert.equal(search([4,5,6,7,0,1,2], 5), 1);
diff --git a/LeetcodeProblemsTests/Algorithms/Search_a_2D_Matrix_II_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Search_a_2D_Matrix_II_Test.js
similarity index 76%
rename from LeetcodeProblemsTests/Algorithms/Search_a_2D_Matrix_II_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Search_a_2D_Matrix_II_Test.js
index 933f5dd..5dff4a5 100644
--- a/LeetcodeProblemsTests/Algorithms/Search_a_2D_Matrix_II_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Search_a_2D_Matrix_II_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const searchMatrix = require("../../LeetcodeProblems/Algorithms/Search_a_2D_Matrix_II").searchMatrix;
+const searchMatrix = require("../../../LeetcodeProblems/Algorithms/medium/Search_a_2D_Matrix_II").searchMatrix;
 
 const matrix1 = [
   [1,4,7,    11,15],
diff --git a/LeetcodeProblemsTests/Algorithms/Search_a_2D_Matrix_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Search_a_2D_Matrix_Test.js
similarity index 75%
rename from LeetcodeProblemsTests/Algorithms/Search_a_2D_Matrix_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Search_a_2D_Matrix_Test.js
index f5e7380..f07b9c0 100644
--- a/LeetcodeProblemsTests/Algorithms/Search_a_2D_Matrix_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Search_a_2D_Matrix_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const searchMatrix = require("../../LeetcodeProblems/Algorithms/Search_a_2D_Matrix").searchMatrix;
+const searchMatrix = require("../../../LeetcodeProblems/Algorithms/medium/Search_a_2D_Matrix").searchMatrix;
 
 var test = function() {
   assert.equal(searchMatrix([], 0), false);
diff --git a/LeetcodeProblemsTests/Algorithms/Simplify_Path_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Simplify_Path_Test.js
similarity index 81%
rename from LeetcodeProblemsTests/Algorithms/Simplify_Path_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Simplify_Path_Test.js
index 8815e3d..0b0c1ce 100644
--- a/LeetcodeProblemsTests/Algorithms/Simplify_Path_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Simplify_Path_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const simplifyPath = require("../../LeetcodeProblems/Algorithms/Simplify_Path").simplifyPath;
+const simplifyPath = require("../../../LeetcodeProblems/Algorithms/medium/Simplify_Path").simplifyPath;
 
 var test = function() { 
   assert.equal(simplifyPath("/../c"), "/c");
diff --git a/LeetcodeProblemsTests/Algorithms/Spiral_Matrix_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Spiral_Matrix_Test.js
similarity index 70%
rename from LeetcodeProblemsTests/Algorithms/Spiral_Matrix_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Spiral_Matrix_Test.js
index ff56856..8002ee5 100644
--- a/LeetcodeProblemsTests/Algorithms/Spiral_Matrix_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Spiral_Matrix_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const spiralOrder = require("../../LeetcodeProblems/Algorithms/Spiral_Matrix").spiralOrder;
+const spiralOrder = require("../../../LeetcodeProblems/Algorithms/medium/Spiral_Matrix").spiralOrder;
 
 var test = function() {
   const matrix = [
diff --git a/LeetcodeProblemsTests/Algorithms/Subarray_Sum_Equals_K_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Subarray_Sum_Equals_K_Test.js
similarity index 72%
rename from LeetcodeProblemsTests/Algorithms/Subarray_Sum_Equals_K_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Subarray_Sum_Equals_K_Test.js
index 1b3481b..8c85c57 100644
--- a/LeetcodeProblemsTests/Algorithms/Subarray_Sum_Equals_K_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Subarray_Sum_Equals_K_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const subarraySum = require("../../LeetcodeProblems/Algorithms/Subarray_Sum_Equals_K").subarraySum;
+const subarraySum = require("../../../LeetcodeProblems/Algorithms/medium/Subarray_Sum_Equals_K").subarraySum;
 
 var test  = function() {
   assert.strictEqual(subarraySum([1,1,1], 2), 2);
diff --git a/LeetcodeProblemsTests/Algorithms/Subsets_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Subsets_Test.js
similarity index 79%
rename from LeetcodeProblemsTests/Algorithms/Subsets_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Subsets_Test.js
index c175b83..de1a1b1 100644
--- a/LeetcodeProblemsTests/Algorithms/Subsets_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Subsets_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const subsets = require("../../LeetcodeProblems/Algorithms/Subsets").subsets;
+const subsets = require("../../../LeetcodeProblems/Algorithms/medium/Subsets").subsets;
 
 function test() {
   assert.deepEqual(subsets([]), [[]]);
diff --git a/LeetcodeProblemsTests/Algorithms/Swap_Nodes_In_Pairs_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Swap_Nodes_In_Pairs_Test.js
similarity index 61%
rename from LeetcodeProblemsTests/Algorithms/Swap_Nodes_In_Pairs_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Swap_Nodes_In_Pairs_Test.js
index 06df05e..5a34ed4 100644
--- a/LeetcodeProblemsTests/Algorithms/Swap_Nodes_In_Pairs_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Swap_Nodes_In_Pairs_Test.js
@@ -1,7 +1,7 @@
 // const assert = require("assert");
-const ListNode = require("../../UtilsClasses/ListNode").ListNode;
-const ListNodeTestHelper = require("../../UtilsClasses/ListNodeTestHelper");
-const swapPairs = require("../../LeetcodeProblems/Algorithms/Swap_Nodes_In_Pairs").swapPairs;
+const ListNode = require("../../../UtilsClasses/ListNode").ListNode;
+const ListNodeTestHelper = require("../../../UtilsClasses/ListNodeTestHelper");
+const swapPairs = require("../../../LeetcodeProblems/Algorithms/medium/Swap_Nodes_In_Pairs").swapPairs;
 
 var test = function () {
   ListNodeTestHelper.assertList(swapPairs(ListNode.linkenList([1,2,3,4])), [2,1,4,3]);
diff --git a/LeetcodeProblemsTests/Algorithms/Time_Needed_Rearrange_Binary_String_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Time_Needed_Rearrange_Binary_String_Test.js
similarity index 56%
rename from LeetcodeProblemsTests/Algorithms/Time_Needed_Rearrange_Binary_String_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Time_Needed_Rearrange_Binary_String_Test.js
index a51e1bf..ba01f9c 100644
--- a/LeetcodeProblemsTests/Algorithms/Time_Needed_Rearrange_Binary_String_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Time_Needed_Rearrange_Binary_String_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const secondsToRemoveOccurrences = require("../../LeetcodeProblems/Algorithms/Time_Needed_Rearrange_Binary_String").secondsToRemoveOccurrences;
+const secondsToRemoveOccurrences = require("../../../LeetcodeProblems/Algorithms/medium/Time_Needed_Rearrange_Binary_String").secondsToRemoveOccurrences;
 
 function test() {
   assert.equal(secondsToRemoveOccurrences("0110101"), 4);
diff --git a/LeetcodeProblemsTests/Algorithms/Top_K_Frequent_Elements_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Top_K_Frequent_Elements_Test.js
similarity index 71%
rename from LeetcodeProblemsTests/Algorithms/Top_K_Frequent_Elements_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Top_K_Frequent_Elements_Test.js
index 5fc89a1..6ccb077 100644
--- a/LeetcodeProblemsTests/Algorithms/Top_K_Frequent_Elements_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Top_K_Frequent_Elements_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const topKFrequent = require("../../LeetcodeProblems/Algorithms/Top_K_Frequent_Elements").topKFrequent;
+const topKFrequent = require("../../../LeetcodeProblems/Algorithms/medium/Top_K_Frequent_Elements").topKFrequent;
 
 var test = function () {
   assert.deepEqual(topKFrequent([1,1,1,2,2,3], 2).sort(), [1,2]);
diff --git a/LeetcodeProblemsTests/Algorithms/Unique_Binary_Search_Trees_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Unique_Binary_Search_Trees_Test.js
similarity index 62%
rename from LeetcodeProblemsTests/Algorithms/Unique_Binary_Search_Trees_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Unique_Binary_Search_Trees_Test.js
index 5a10c4a..96f28e2 100644
--- a/LeetcodeProblemsTests/Algorithms/Unique_Binary_Search_Trees_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Unique_Binary_Search_Trees_Test.js
@@ -1,7 +1,7 @@
 const assert = require("assert");
-const numTrees1 = require("../../LeetcodeProblems/Algorithms/Unique_Binary_Search_Trees").numTrees1;
-const numTrees2 = require("../../LeetcodeProblems/Algorithms/Unique_Binary_Search_Trees").numTrees2;
-const numTrees3 = require("../../LeetcodeProblems/Algorithms/Unique_Binary_Search_Trees").numTrees3;
+const numTrees1 = require("../../../LeetcodeProblems/Algorithms/medium/Unique_Binary_Search_Trees").numTrees1;
+const numTrees2 = require("../../../LeetcodeProblems/Algorithms/medium/Unique_Binary_Search_Trees").numTrees2;
+const numTrees3 = require("../../../LeetcodeProblems/Algorithms/medium/Unique_Binary_Search_Trees").numTrees3;
 
 var test = function () {
   assert.strictEqual(numTrees1(1), 1);
diff --git a/LeetcodeProblemsTests/Algorithms/Unique_Paths_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Unique_Paths_Test.js
similarity index 54%
rename from LeetcodeProblemsTests/Algorithms/Unique_Paths_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Unique_Paths_Test.js
index a67592a..9330218 100644
--- a/LeetcodeProblemsTests/Algorithms/Unique_Paths_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Unique_Paths_Test.js
@@ -1,7 +1,7 @@
 const assert = require("assert");
-const uniquePaths1 = require("../../LeetcodeProblems/Algorithms/Unique_Paths").uniquePaths1;
-const uniquePaths2 = require("../../LeetcodeProblems/Algorithms/Unique_Paths").uniquePaths2;
-const uniquePaths3 = require("../../LeetcodeProblems/Algorithms/Unique_Paths").uniquePaths3;
+const uniquePaths1 = require("../../../LeetcodeProblems/Algorithms/medium/Unique_Paths").uniquePaths1;
+const uniquePaths2 = require("../../../LeetcodeProblems/Algorithms/medium/Unique_Paths").uniquePaths2;
+const uniquePaths3 = require("../../../LeetcodeProblems/Algorithms/medium/Unique_Paths").uniquePaths3;
 
 var test = function() {
   assert.strictEqual(uniquePaths1(10,4), 220);
diff --git a/LeetcodeProblemsTests/Algorithms/Verify_Preorder_Serialization_of_a_Binary_Tree_Test.js b/LeetcodeProblemsTests/Algorithms/medium/Verify_Preorder_Serialization_of_a_Binary_Tree_Test.js
similarity index 75%
rename from LeetcodeProblemsTests/Algorithms/Verify_Preorder_Serialization_of_a_Binary_Tree_Test.js
rename to LeetcodeProblemsTests/Algorithms/medium/Verify_Preorder_Serialization_of_a_Binary_Tree_Test.js
index ad60f96..9bab778 100644
--- a/LeetcodeProblemsTests/Algorithms/Verify_Preorder_Serialization_of_a_Binary_Tree_Test.js
+++ b/LeetcodeProblemsTests/Algorithms/medium/Verify_Preorder_Serialization_of_a_Binary_Tree_Test.js
@@ -1,5 +1,5 @@
 const assert = require("assert");
-const isValidSerialization = require("../../LeetcodeProblems/Algorithms/Verify_Preorder_Serialization_of_a_Binary_Tree").isValidSerialization;
+const isValidSerialization = require("../../../LeetcodeProblems/Algorithms/medium/Verify_Preorder_Serialization_of_a_Binary_Tree").isValidSerialization;
 
 var test = function() {
   assert.strictEqual(isValidSerialization(""), true);
diff --git a/README.md b/README.md
index 0b2e13d..cc94197 100644
--- a/README.md
+++ b/README.md
@@ -15,84 +15,85 @@ The solutions are located under `/LeetcodeProblems`. Each problem has a test fil
 
 | Name | Level | Link | 
 | - | - | - |
-| [Edit Distance ](/LeetcodeProblems/Algorithms/Edit_Distance.js)                                                 | Hard   | https://leetcode.com/problems/edit-distance/ |
-| [Remove Invalid Parentheses ](/LeetcodeProblems/Algorithms/Remove_Invalid_Parentheses.js)                       | Hard   | https://leetcode.com/problems/remove-invalid-parentheses/ |
-| [Longest Consecutive Sequence ](/LeetcodeProblems/Algorithms/Longest_Consecutive_Sequence.js)                   | Hard   | https://leetcode.com/problems/longest-consecutive-sequence/ |
-| [Minimum Window Substring ](/LeetcodeProblems/Algorithms/Minimum_Window_Substring.js)                           | Hard   | https://leetcode.com/problems/minimum-window-substring/ |
-| [Regular Expression Matching ](/LeetcodeProblems/Algorithms/Regular_Expression_Matching.js)                     | Hard   | https://leetcode.com/problems/regular-expression-matching/ |
-| [NQueens ](/LeetcodeProblems/Algorithms/NQueens.js)                                                             | Hard   | https://leetcode.com/problems/n-queens/ |
-| [merge k sorted lists ](/LeetcodeProblems/Algorithms/merge_k_sorted_lists.js)                                   | Hard   | https://leetcode.com/problems/merge-k-sorted-lists/ |
-| [Set Matrix Zeroes](/LeetcodeProblems/Algorithms/Set_Matrix_Zeroes.js)                                          | Hard   | https://leetcode.com/problems/set-matrix-zeroes/ |
-| [Subarray Sum Equals K ](/LeetcodeProblems/Algorithms/Subarray_Sum_Equals_K.js)                                 | Medium | https://leetcode.com/problems/subarray-sum-equals-k/ | 
-| [3Sum Closest](/LeetcodeProblems/Algorithms/3SumClosest.js)                                                     | Medium | https://leetcode.com/problems/3sum-closest/ | 
-| [3Sum ](/LeetcodeProblems/Algorithms/3Sum.js)                                                                   | Medium | https://leetcode.com/problems/3sum/ | 
-| [NumberOfIslands ](/LeetcodeProblems/Algorithms/Number_of_Islands.js)                                           | Medium | https://leetcode.com/problems/number-of-islands/ | 
-| [Swap Nodes in Pairs](/LeetcodeProblems/Algorithms/Swap_Nodes_in_Pairs.js)                                      | Medium | https://leetcode.com/problems/swap-nodes-in-pairs/ | 
-| [Add Two Numbers ](/LeetcodeProblems/Algorithms/Add_Two_Numbers.js)                                             | Medium | https://leetcode.com/problems/add-two-numbers/  |
-| [Clone Graph ](/LeetcodeProblems/Algorithms/Clone_Graph.js)                                                     | Medium | https://leetcode.com/problems/clone-graph/ |
-| [Coin Change ](/LeetcodeProblems/Algorithms/Coin_Change.js)                                                     | Medium | https://leetcode.com/problems/coin-change/ |
-| [Container With Most Water](/LeetcodeProblems/Algorithms/Container_With_Most_Water.js)                          | Medium | https://leetcode.com/problems/container-with-most-water/ |
-| [Design Circular Deque ](/LeetcodeProblems/Algorithms/Design_Circular_Deque.js)                                 | Medium | https://leetcode.com/problems/design-circular-deque/
-| [Escape The Ghosts](/LeetcodeProblems/Algorithms/Escape_The_Ghosts.js)                                          | Medium | https://leetcode.com/problems/escape-the-ghosts/ |
-| [Find All Anagrams in a String](/LeetcodeProblems/Algorithms/Find_Anagrams.js)                                  | Medium | https://leetcode.com/problems/find-all-anagrams-in-a-string/ |
-| [Generate Parenthesis ](/LeetcodeProblems/Algorithms/Generate_Parenthesis.js)                                   | Medium | https://leetcode.com/problems/generate-parentheses | 
-| [Group Anagrams ](/LeetcodeProblems/Algorithms/Group_Anagrams.js)                                               | Medium | https://leetcode.com/problems/group-anagrams/
-| [Kth Largest Element in an Array ](/LeetcodeProblems/Algorithms/Kth_Largest_Element_in_an_Array.js)             | Medium | https://leetcode.com/problems/kth-largest-element-in-an-array/ |
-| [Linked List Cycle II ](/LeetcodeProblems/Algorithms/Linked_List_Cycle_II.js)                                   | Medium | https://leetcode.com/problems/linked-list-cycle-ii/ |
-| [Longest Palindromic Substring ](/LeetcodeProblems/Algorithms/Longest_Palindromic_Substring.js)                 | Medium | https://leetcode.com/problems/longest-palindromic-substring/|
-| [Longest Substring Without Reapeating Characters](/LeetcodeProblems/Algorithms/Longest_Substring.js)            | Medium | https://leetcode.com/problems/longest-substring-without-repeating-characters|
-| [Max Area Of Island ](/LeetcodeProblems/Algorithms/Max_Area_Of_Island.js)                                       | Medium | https://leetcode.com/problems/max-area-of-island/ |
-| [Max Consecutive Ones III ](/LeetcodeProblems/Algorithms/Max_Consecutive_Ones_III.js)                           | Medium | https://leetcode.com/problems/max-consecutive-ones-iii |
-| [Maximal Square ](/LeetcodeProblems/Algorithms/Maximal_Square.js)                                               | Medium | https://leetcode.com/problems/maximal-square/ |
-| [Minimum Add to Make Parentheses Valid ](/LeetcodeProblems/Algorithms/Minimum_Add_To_Make_Parentheses_Valid.js) | Medium | https://leetcode.com/problems/minimum-add-to-make-parentheses-valid/ |
-| [Minimum Size Subarray](/LeetcodeProblems/Algorithms/Minimum_Size_Subarray.js)                                  | Medium | https://leetcode.com/problems/minimum-size-subarray-sum |
-| [Permutations ](/LeetcodeProblems/Algorithms/Permutations.js)                                                   | Medium | https://leetcode.com/problems/permutations/ |
-| [Permutations II ](/LeetcodeProblems/Algorithms/Permutations_II.js)                                             | Medium | https://leetcode.com/problems/permutations-ii/ |
-| [Permutation in String](/LeetcodeProblems/Algorithms/Permutations_In_String.js)                                 | Medium | https://leetcode.com/problems/permutation-in-string/ |
-| [Permutations Without Duplicates ](/LeetcodeProblems/Algorithms/Permutations_Without_Duplicates.js)             | Medium | https://leetcode.com/problems/permutations/ |
-| [Restore IP Addresses ](/LeetcodeProblems/Algorithms/Restore_IP_Addresses.js)                                   | Medium | https://leetcode.com/problems/restore-ip-addresses/ |
-| [SearchIng Rotated Sorted Array ](/LeetcodeProblems/Algorithms/SearchIng_Rotated_Sorted_Array.js)               | Medium | https://leetcode.com/problems/search-in-rotated-sorted-array/ |
-| [Search a 2D Matrix ](/LeetcodeProblems/Algorithms/Search_a_2D_Matrix.js)                                       | Medium | https://leetcode.com/problems/search-a-2d-matrix/ |
-| [Search a 2D Matrix II ](/LeetcodeProblems/Algorithms/Search_a_2D_Matrix_II.js)                                 | Medium | https://leetcode.com/problems/search-a-2d-matrix/ |
-| [Simplify Path ](/LeetcodeProblems/Algorithms/Simplify_Path.js)                                                 | Medium | https://leetcode.com/problems/simplify-path/ |
-| [Spiral Matrix ](/LeetcodeProblems/Algorithms/Spiral_Matrix.js)                                                 | Medium | https://leetcode.com/problems/spiral-matrix/ |
-| [Subsets ](/LeetcodeProblems/Algorithms/Subsets.js)                                                             | Medium | https://leetcode.com/problems/subsets/ |
-| [Unique Binary Search Trees ](/LeetcodeProblems/Algorithms/Unique_Binary_Search_Trees.js)                       | Medium | https://leetcode.com/problems/unique-binary-search-trees/ |
-| [Unique Paths ](/LeetcodeProblems/Algorithms/Unique_Paths.js)                                                   | Medium | https://leetcode.com/problems/unique-paths/ |
-| [Verify Preorder Serialization of a Binary Tree ](/LeetcodeProblems/Algorithms/Verify_Preorder_Serialization_of_a_Binary_Tree.js)              | Medium | https://leetcode.com/problems/verify-preorder-serialization-of-a-binary-tree/ |
-| [Construct Binary Tree from Preorder and Inorder Traversal ](/LeetcodeProblems/Algorithms/Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal.js)   | Medium | https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/ | 
-| [Lowest Common Ancestor of a Binary Tree ](/LeetcodeProblems/Algorithms/Lowest_Common_Ancestor_of_a_Binary_Tree.js) | Medium | https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/ |
-| [Maximum Sum of an Hourglass](/LeetcodeProblems/Algorithms/Maximise_Hour_Glass_Sum.js)                          | Medium | https://leetcode.com/problems/maximum-sum-of-an-hourglass/ |
-| [Next Permutation](/LeetcodeProblems/Algorithms/Next_Permutation.js)                                            | Medium | https://leetcode.com/problems/next-permutation/ |
-| [Time Needed to Rearrange a Binary String](/LeetcodeProblems/Algorithms/Time_Needed_Rearrange_Binary_String.js)| Medium | https://leetcode.com/problems/time-needed-to-rearrange-a-binary-string/ |
-| [Find Subarrays With Equal Sum ](/LeetcodeProblems/Algorithms/Find_Subarrays_With_Equal_Sums.js)                | Medium | https://leetcode.com/problems/find-subarrays-with-equal-sum/ | 
-| [Reverse Integer](/LeetcodeProblems/Algorithms/Reverse_Integer.js)                                              | Medium | https://leetcode.com/problems/reverse-integer/ |
-| [Minimize Maximum Pair Sum in Array ](/LeetcodeProblems/Algorithms/Minimize_Maximum_Pair_Sum_In_Array.js)                                                   | Medium | https://leetcode.com/problems/minimize-maximum-pair-sum-in-array/ |
-| [Top K Frequent Elements ](/LeetcodeProblems/Algorithms/Top_K_Frequent_Elements.js)                                                   | Medium | https://leetcode.com/problems/top-k-frequent-elements/ |
-| [Gas Station](/LeetcodeProblems/Algorithms/GasStation/index.js)                                                | Medium | https://leetcode.com/problems/gas-station/description/|
-| [K Closest Points to Origin](/LeetcodeProblems/Algorithms/K_Closest_Points_to_Origin.js/)                      | Medium | https://leetcode.com/problems/k-closest-points-to-origin/
-| [Flood Fill ](/LeetcodeProblems/Algorithms/Flood_Fill.js)                                                       | Easy   | https://leetcode.com/problems/flood-fill/ |
-| [Implement stack using queues ](/LeetcodeProblems/Algorithms/Implement_stack_using_queues.js)                   | Easy   | https://leetcode.com/problems/implement-stack-using-queues/ |
-| [Number of Segments in a String ](/LeetcodeProblems/Algorithms/Number_of_Segments_in_a_String.js)               | Easy   | https://leetcode.com/problems/number-of-segments-in-a-string/ |
-| [Maximun Subarray ](/LeetcodeProblems/Algorithms/Maximun_Subarray.js)                                           | Easy   | https://leetcode.com/problems/maximum-subarray |
-| [Min Stack ](/LeetcodeProblems/Algorithms/Min_Stack.js)                                                         | Easy   | https://leetcode.com/problems/min-stack/ |  
-| [Reverse String II ](/LeetcodeProblems/Algorithms/Reverse_String_II.js)                                         | Easy   | https://leetcode.com/problems/reverse-string-ii/ | 
-| [Same Tree ](/LeetcodeProblems/Algorithms/Same_Tree.js)                                                         | Easy   | https://leetcode.com/problems/same-tree/ |
-| [Sum Of Square Numbers ](/LeetcodeProblems/Algorithms/Sum_Of_Square_Numbers.js)                                 | Easy   | https://leetcode.com/problems/sum-of-square-numbers/ |
-| [Symmetric Tree ](/LeetcodeProblems/Algorithms/Symmetric_Tree.js)                                               | Easy   | https://leetcode.com/problems/symmetric-tree/ |
-| [Valid Parentheses ](/LeetcodeProblems/Algorithms/Valid_Parentheses.js)                                         | Easy   | https://leetcode.com/problems/valid-parentheses/ |
-| [Backspace String Compare ](/LeetcodeProblems/Algorithms/Backspace_String_Compare.js)                           | Easy   | https://leetcode.com/problems/backspace-string-compare/ |
-| [Binary Gap ](/LeetcodeProblems/Algorithms/Binary_Gap.js)                                                       | Easy   | https://leetcode.com/problems/binary-gap/ |
-| [Binary Gap ](/LeetcodeProblems/Algorithms/Binary_Gap.js)                                                       | Easy   | https://leetcode.com/problems/binary-gap/ |
-| [Majority Element](/LeetcodeProblems/Algorithms/Majority_Element.js)                                            | Easy   | https://leetcode.com/problems/majority-element/ |
-| [Longest Common Prefix](/LeetcodeProblems/Algorithms/Longest_Common_Prefix.js)                                  | Easy   | https://leetcode.com/problems/longest-common-prefix/ |
-| [Two Sum](/LeetcodeProblems/Algorithms/2Sum.js)                                                                 | Easy   | https://leetcode.com/problems/two-sum/ |
-| [Tic Tac Toe ](/LeetcodeProblems/Algorithms/Tic_Tac_Toe.js)                                                     |        | |
-| [Permutations With Duplicates ](/LeetcodeProblems/Algorithms/Permutations_With_Duplicates.js)                   |        | |
-| [Deletion Distance](/LeetcodeProblems/Algorithms/Deletion_Distance.js)                                          |        | |
-| [Award Budget Cuts](/LeetcodeProblems/Algorithms/Award_Budget_Cuts.js)                                          |        | |
-| [Happy Number](https://leetcode.com/problems/happy-number/)                                                     | Easy   | https://leetcode.com/problems/happy-number/ |
-| [Shuffle String](https://leetcode.com/problems/shuffle-string/)                                                 | Easy   | https://leetcode.com/problems/shuffle-string/ |
+| [Edit Distance ](/LeetcodeProblems/Algorithms/hard/Edit_Distance.js)                                            | Hard   | https://leetcode.com/problems/edit-distance/ |
+| [Remove Invalid Parentheses ](/LeetcodeProblems/Algorithms/hard/Remove_Invalid_Parentheses.js)                  | Hard   | https://leetcode.com/problems/remove-invalid-parentheses/ |
+| [Longest Consecutive Sequence ](/LeetcodeProblems/Algorithms/hard/Longest_Consecutive_Sequence.js)              | Hard   | https://leetcode.com/problems/longest-consecutive-sequence/ |
+| [Minimum Window Substring ](/LeetcodeProblems/Algorithms/hard/Minimum_Window_Substring.js)                      | Hard   | https://leetcode.com/problems/minimum-window-substring/ |
+| [Regular Expression Matching ](/LeetcodeProblems/Algorithms/hard/Regular_Expression_Matching.js)                | Hard   | https://leetcode.com/problems/regular-expression-matching/ |
+| [NQueens ](/LeetcodeProblems/Algorithms/hard/NQueens.js)                                                        | Hard   | https://leetcode.com/problems/n-queens/ |
+| [merge k sorted lists ](/LeetcodeProblems/Algorithms/hard/merge_k_sorted_lists.js)                              | Hard   | https://leetcode.com/problems/merge-k-sorted-lists/ |
+| [Set Matrix Zeroes](/LeetcodeProblems/Algorithms/hard/Set_Matrix_Zeroes.js)                                     | Hard   | https://leetcode.com/problems/set-matrix-zeroes/ |
+| [Subarray Sum Equals K ](/LeetcodeProblems/Algorithms/medium/Subarray_Sum_Equals_K.js)                                 | Medium | https://leetcode.com/problems/subarray-sum-equals-k/ | 
+| [3Sum Closest](/LeetcodeProblems/Algorithms/medium/3SumClosest.js)                                                     | Medium | https://leetcode.com/problems/3sum-closest/ | 
+| [3Sum ](/LeetcodeProblems/Algorithms/medium/3Sum.js)                                                                   | Medium | https://leetcode.com/problems/3sum/ | 
+| [NumberOfIslands ](/LeetcodeProblems/Algorithms/medium/Number_of_Islands.js)                                           | Medium | https://leetcode.com/problems/number-of-islands/ | 
+| [Swap Nodes in Pairs](/LeetcodeProblems/Algorithms/medium/Swap_Nodes_in_Pairs.js)                                      | Medium | https://leetcode.com/problems/swap-nodes-in-pairs/ | 
+| [Add Two Numbers ](/LeetcodeProblems/Algorithms/medium/Add_Two_Numbers.js)                                             | Medium | https://leetcode.com/problems/add-two-numbers/  |
+| [Clone Graph ](/LeetcodeProblems/Algorithms/medium/Clone_Graph.js)                                                     | Medium | https://leetcode.com/problems/clone-graph/ |
+| [Coin Change ](/LeetcodeProblems/Algorithms/medium/Coin_Change.js)                                                     | Medium | https://leetcode.com/problems/coin-change/ |
+| [Container With Most Water](/LeetcodeProblems/Algorithms/medium/Container_With_Most_Water.js)                          | Medium | https://leetcode.com/problems/container-with-most-water/ |
+| [Design Circular Deque ](/LeetcodeProblems/Algorithms/medium/Design_Circular_Deque.js)                                 | Medium | https://leetcode.com/problems/design-circular-deque/
+| [Escape The Ghosts](/LeetcodeProblems/Algorithms/medium/Escape_The_Ghosts.js)                                          | Medium | https://leetcode.com/problems/escape-the-ghosts/ |
+| [Find All Anagrams in a String](/LeetcodeProblems/Algorithms/medium/Find_Anagrams.js)                                  | Medium | https://leetcode.com/problems/find-all-anagrams-in-a-string/ |
+| [Generate Parenthesis ](/LeetcodeProblems/Algorithms/medium/Generate_Parenthesis.js)                                   | Medium | https://leetcode.com/problems/generate-parentheses | 
+| [Group Anagrams ](/LeetcodeProblems/Algorithms/medium/Group_Anagrams.js)                                               | Medium | https://leetcode.com/problems/group-anagrams/
+| [Kth Largest Element in an Array ](/LeetcodeProblems/Algorithms/medium/Kth_Largest_Element_in_an_Array.js)             | Medium | https://leetcode.com/problems/kth-largest-element-in-an-array/ |
+| [Linked List Cycle II ](/LeetcodeProblems/Algorithms/medium/Linked_List_Cycle_II.js)                                   | Medium | https://leetcode.com/problems/linked-list-cycle-ii/ |
+| [Longest Palindromic Substring ](/LeetcodeProblems/Algorithms/medium/Longest_Palindromic_Substring.js)                 | Medium | https://leetcode.com/problems/longest-palindromic-substring/|
+| [Longest Substring Without Reapeating Characters](/LeetcodeProblems/Algorithms/medium/Longest_Substring.js)            | Medium | https://leetcode.com/problems/longest-substring-without-repeating-characters|
+| [Max Area Of Island ](/LeetcodeProblems/Algorithms/medium/Max_Area_Of_Island.js)                                       | Medium | https://leetcode.com/problems/max-area-of-island/ |
+| [Max Consecutive Ones III ](/LeetcodeProblems/Algorithms/medium/Max_Consecutive_Ones_III.js)                           | Medium | https://leetcode.com/problems/max-consecutive-ones-iii |
+| [Maximal Square ](/LeetcodeProblems/Algorithms/medium/Maximal_Square.js)                                               | Medium | https://leetcode.com/problems/maximal-square/ |
+| [Minimum Add to Make Parentheses Valid ](/LeetcodeProblems/Algorithms/medium/Minimum_Add_To_Make_Parentheses_Valid.js) | Medium | https://leetcode.com/problems/minimum-add-to-make-parentheses-valid/ |
+| [Minimum Size Subarray](/LeetcodeProblems/Algorithms/medium/Minimum_Size_Subarray.js)                                  | Medium | https://leetcode.com/problems/minimum-size-subarray-sum |
+| [Permutations ](/LeetcodeProblems/Algorithms/medium/Permutations.js)                                                   | Medium | https://leetcode.com/problems/permutations/ |
+| [Permutations II ](/LeetcodeProblems/Algorithms/medium/Permutations_II.js)                                             | Medium | https://leetcode.com/problems/permutations-ii/ |
+| [Permutation in String](/LeetcodeProblems/Algorithms/medium/Permutations_In_String.js)                                 | Medium | https://leetcode.com/problems/permutation-in-string/ |
+| [Permutations Without Duplicates ](/LeetcodeProblems/Algorithms/medium/Permutations_Without_Duplicates.js)             | Medium | https://leetcode.com/problems/permutations/ |
+| [Restore IP Addresses ](/LeetcodeProblems/Algorithms/medium/Restore_IP_Addresses.js)                                   | Medium | https://leetcode.com/problems/restore-ip-addresses/ |
+| [SearchIng Rotated Sorted Array ](/LeetcodeProblems/Algorithms/medium/SearchIng_Rotated_Sorted_Array.js)               | Medium | https://leetcode.com/problems/search-in-rotated-sorted-array/ |
+| [Search a 2D Matrix ](/LeetcodeProblems/Algorithms/medium/Search_a_2D_Matrix.js)                                       | Medium | https://leetcode.com/problems/search-a-2d-matrix/ |
+| [Search a 2D Matrix II ](/LeetcodeProblems/Algorithms/medium/Search_a_2D_Matrix_II.js)                                 | Medium | https://leetcode.com/problems/search-a-2d-matrix/ |
+| [Simplify Path ](/LeetcodeProblems/Algorithms/medium/Simplify_Path.js)                                                 | Medium | https://leetcode.com/problems/simplify-path/ |
+| [Spiral Matrix ](/LeetcodeProblems/Algorithms/medium/Spiral_Matrix.js)                                                 | Medium | https://leetcode.com/problems/spiral-matrix/ |
+| [Subsets ](/LeetcodeProblems/Algorithms/medium/Subsets.js)                                                             | Medium | https://leetcode.com/problems/subsets/ |
+| [Unique Binary Search Trees ](/LeetcodeProblems/Algorithms/medium/Unique_Binary_Search_Trees.js)                       | Medium | https://leetcode.com/problems/unique-binary-search-trees/ |
+| [Unique Paths ](/LeetcodeProblems/Algorithms/medium/Unique_Paths.js)                                                   | Medium | https://leetcode.com/problems/unique-paths/ |
+| [Verify Preorder Serialization of a Binary Tree ](/LeetcodeProblems/Algorithms/medium/Verify_Preorder_Serialization_of_a_Binary_Tree.js)              | Medium | https://leetcode.com/problems/verify-preorder-serialization-of-a-binary-tree/ |
+| [Construct Binary Tree from Preorder and Inorder Traversal ](/LeetcodeProblems/Algorithms/medium/Construct_Binary_Tree_from_Preorder_and_Inorder_Traversal.js)   | Medium | https://leetcode.com/problems/construct-binary-tree-from-preorder-and-inorder-traversal/ | 
+| [Lowest Common Ancestor of a Binary Tree ](/LeetcodeProblems/Algorithms/medium/Lowest_Common_Ancestor_of_a_Binary_Tree.js) | Medium | https://leetcode.com/problems/lowest-common-ancestor-of-a-binary-tree/ |
+| [Maximum Sum of an Hourglass](/LeetcodeProblems/Algorithms/medium/Maximise_Hour_Glass_Sum.js)                          | Medium | https://leetcode.com/problems/maximum-sum-of-an-hourglass/ |
+| [Next Permutation](/LeetcodeProblems/Algorithms/medium/Next_Permutation.js)                                            | Medium | https://leetcode.com/problems/next-permutation/ |
+| [Time Needed to Rearrange a Binary String](/LeetcodeProblems/Algorithms/medium/Time_Needed_Rearrange_Binary_String.js)| Medium | https://leetcode.com/problems/time-needed-to-rearrange-a-binary-string/ |
+| [Find Subarrays With Equal Sum ](/LeetcodeProblems/Algorithms/medium/Find_Subarrays_With_Equal_Sums.js)                | Medium | https://leetcode.com/problems/find-subarrays-with-equal-sum/ | 
+| [Reverse Integer](/LeetcodeProblems/Algorithms/medium/Reverse_Integer.js)                                              | Medium | https://leetcode.com/problems/reverse-integer/ |
+| [Minimize Maximum Pair Sum in Array ](/LeetcodeProblems/Algorithms/medium/Minimize_Maximum_Pair_Sum_In_Array.js)                                                   | Medium | https://leetcode.com/problems/minimize-maximum-pair-sum-in-array/ |
+| [Top K Frequent Elements ](/LeetcodeProblems/Algorithms/medium/Top_K_Frequent_Elements.js)                                                   | Medium | https://leetcode.com/problems/top-k-frequent-elements/ |
+| [Gas Station](/LeetcodeProblems/Algorithms/medium/GasStation/index.js)                                                | Medium | https://leetcode.com/problems/gas-station/description/|
+| [K Closest Points to Origin](/LeetcodeProblems/Algorithms/medium/K_Closest_Points_to_Origin.js/)                      | Medium | https://leetcode.com/problems/k-closest-points-to-origin/
+| [BestTimeToBuy](LeetcodeProblems/Algorithms/easy/Best_Time_To_Buy_And_Sell_Stock_II.js)                              | Medium | https://leetcode.com/problems/best-time-to-buy-and-sell-stock-ii |
+| [Flood Fill ](/LeetcodeProblems/Algorithms/easy/Flood_Fill.js)                                                       | Easy   | https://leetcode.com/problems/flood-fill/ |
+| [Implement stack using queues ](/LeetcodeProblems/Algorithms/easy/Implement_stack_using_queues.js)                   | Easy   | https://leetcode.com/problems/implement-stack-using-queues/ |
+| [Number of Segments in a String ](/LeetcodeProblems/Algorithms/easy/Number_of_Segments_in_a_String.js)               | Easy   | https://leetcode.com/problems/number-of-segments-in-a-string/ |
+| [Maximun Subarray ](/LeetcodeProblems/Algorithms/easy/Maximun_Subarray.js)                                           | Easy   | https://leetcode.com/problems/maximum-subarray |
+| [Min Stack ](/LeetcodeProblems/Algorithms/easy/Min_Stack.js)                                                         | Easy   | https://leetcode.com/problems/min-stack/ |  
+| [Reverse String II ](/LeetcodeProblems/Algorithms/easy/Reverse_String_II.js)                                         | Easy   | https://leetcode.com/problems/reverse-string-ii/ | 
+| [Same Tree ](/LeetcodeProblems/Algorithms/easy/Same_Tree.js)                                                         | Easy   | https://leetcode.com/problems/same-tree/ |
+| [Sum Of Square Numbers ](/LeetcodeProblems/Algorithms/easy/Sum_Of_Square_Numbers.js)                                 | Easy   | https://leetcode.com/problems/sum-of-square-numbers/ |
+| [Symmetric Tree ](/LeetcodeProblems/Algorithms/easy/Symmetric_Tree.js)                                               | Easy   | https://leetcode.com/problems/symmetric-tree/ |
+| [Valid Parentheses ](/LeetcodeProblems/Algorithms/easy/Valid_Parentheses.js)                                         | Easy   | https://leetcode.com/problems/valid-parentheses/ |
+| [Backspace String Compare ](/LeetcodeProblems/Algorithms/easy/Backspace_String_Compare.js)                           | Easy   | https://leetcode.com/problems/backspace-string-compare/ |
+| [Binary Gap ](/LeetcodeProblems/Algorithms/easy/Binary_Gap.js)                                                       | Easy   | https://leetcode.com/problems/binary-gap/ |
+| [Binary Gap ](/LeetcodeProblems/Algorithms/easy/Binary_Gap.js)                                                       | Easy   | https://leetcode.com/problems/binary-gap/ |
+| [Majority Element](/LeetcodeProblems/Algorithms/easy/Majority_Element.js)                                            | Easy   | https://leetcode.com/problems/majority-element/ |
+| [Longest Common Prefix](/LeetcodeProblems/Algorithms/easy/Longest_Common_Prefix.js)                                  | Easy   | https://leetcode.com/problems/longest-common-prefix/ |
+| [Two Sum](/LeetcodeProblems/Algorithms/easy/2Sum.js)                                                                 | Easy   | https://leetcode.com/problems/two-sum/ |
+| [Tic Tac Toe ](/LeetcodeProblems/Algorithms/easy/Tic_Tac_Toe.js)                                                     | Easy   | |
+| [Permutations With Duplicates ](/LeetcodeProblems/Algorithms/easy/Permutations_With_Duplicates.js)                   | Easy   | |
+| [Deletion Distance](/LeetcodeProblems/Algorithms/easy/Deletion_Distance.js)                                          | Easy   | |
+| [Award Budget Cuts](/LeetcodeProblems/Algorithms/easy/Award_Budget_Cuts.js)                                          | Easy   | |
+| [Happy Number](/LeetcodeProblems/Algorithms/easy/Happy_Number.js)                                                    | Easy   | https://leetcode.com/problems/happy-number/ |
+| [Shuffle String](/LeetcodeProblems/Algorithms/easy/Shuffle_String.js)                                                | Easy   | https://leetcode.com/problems/shuffle-string/ |
 
 ### Sorting Algorithms
 | Algoritmhs |
@@ -103,20 +104,20 @@ The solutions are located under `/LeetcodeProblems`. Each problem has a test fil
 ### Databases
 | Problems | Level | Link |
 |-|-|-|
-| [Trips and Users](/LeetcodeProblems/Databases/Trips_and_Users.sql) | Hard | https://leetcode.com/problems/trips-and-users/ |
-| [Human Traffic of Stadium](/LeetcodeProblems/Databases/Human_Traffic_of_Stadium.sql) | Hard | https://leetcode.com/problems/human-traffic-of-stadium |
-| [Rank Scores](/LeetcodeProblems/Databases/Rank_Scores.sql) | Medium | https://leetcode.com/problems/rank-scores |
-| [Consecutive Numbers](/LeetcodeProblems/Databases/Consecutive_Numbers.sql) | Medium | https://leetcode.com/problems/consecutive-numbers |
-| [Department Highest Salary](/LeetcodeProblems/Databases/Department_Highest_Salary.sql) | Medium | https://leetcode.com/problems/department-highest-salary |
-| [Exchange Seats](/LeetcodeProblems/Databases/Exchange_Seats.sql) | Medium | https://leetcode.com/problems/exchange-seats |
-| [Nth Highest Salary](/LeetcodeProblems/Databases/nth_Highest_Salary.sql) | Medium | https://leetcode.com/problems/nth-highest-salary |
-| [Combine Two Tables](/LeetcodeProblems/Databases/Combine_Two_Tables.sql) | Easy   | https://leetcode.com/problems/combine-two-tables |
-| [Second Highest Salary](/LeetcodeProblems/Databases/Second_highest_salary.sql)| Easy   | https://leetcode.com/problems/second-highest-salary |
-| [Customers Who Never Order](/LeetcodeProblems/Databases/Customers_Who_Never_Order.sql)| Easy |  https://leetcode.com/problems/customers-who-never-order |
-| [Reformat Department Table](/LeetcodeProblems/Databases/Reformat_Department_Table.sql) | Easy | https://leetcode.com/problems/reformat-department-table |
-| [Employees Earning More Than Their Managers](/LeetcodeProblems/Databases/Employees_Earning_More_Than_Their_Managers.sql) | Easy | https://leetcode.com/problems/employees-earning-more-than-their-managers/ |
-| [Delete Duplicate Emails](LeetcodeProblems/Databases/Delete_Duplicate_Emails.sql) | Easy | https://leetcode.com/problems/delete-duplicate-emails |
-| [Rising Temperature](LeetcodeProblems/Databases/Rising_Temperature.sql) | Easy | https://leetcode.com/problems/rising-temperature |
+| [Trips and Users](/LeetcodeProblems/Databases/hard/Trips_and_Users.sql) | Hard | https://leetcode.com/problems/trips-and-users/ |
+| [Human Traffic of Stadium](/LeetcodeProblems/Databases/hard/Human_Traffic_of_Stadium.sql) | Hard | https://leetcode.com/problems/human-traffic-of-stadium |
+| [Rank Scores](/LeetcodeProblems/Databases/medium/Rank_Scores.sql) | Medium | https://leetcode.com/problems/rank-scores |
+| [Consecutive Numbers](/LeetcodeProblems/Databases/medium/Consecutive_Numbers.sql) | Medium | https://leetcode.com/problems/consecutive-numbers |
+| [Department Highest Salary](/LeetcodeProblems/Databases/medium/Department_Highest_Salary.sql) | Medium | https://leetcode.com/problems/department-highest-salary |
+| [Exchange Seats](/LeetcodeProblems/Databases/medium/Exchange_Seats.sql) | Medium | https://leetcode.com/problems/exchange-seats |
+| [Nth Highest Salary](/LeetcodeProblems/Databases/medium/nth_Highest_Salary.sql) | Medium | https://leetcode.com/problems/nth-highest-salary |
+| [Combine Two Tables](/LeetcodeProblems/Databases/easy/Combine_Two_Tables.sql) | Easy   | https://leetcode.com/problems/combine-two-tables |
+| [Second Highest Salary](/LeetcodeProblems/Databases/easy/Second_highest_salary.sql)| Easy   | https://leetcode.com/problems/second-highest-salary |
+| [Customers Who Never Order](/LeetcodeProblems/Databases/easy/Customers_Who_Never_Order.sql)| Easy |  https://leetcode.com/problems/customers-who-never-order |
+| [Reformat Department Table](/LeetcodeProblems/Databases/easy/Reformat_Department_Table.sql) | Easy | https://leetcode.com/problems/reformat-department-table |
+| [Employees Earning More Than Their Managers](/LeetcodeProblems/Databases/easy/Employees_Earning_More_Than_Their_Managers.sql) | Easy | https://leetcode.com/problems/employees-earning-more-than-their-managers/ |
+| [Delete Duplicate Emails](LeetcodeProblems/Databases/easy/Delete_Duplicate_Emails.sql) | Easy | https://leetcode.com/problems/delete-duplicate-emails |
+| [Rising Temperature](LeetcodeProblems/Databases/easy/Rising_Temperature.sql) | Easy | https://leetcode.com/problems/rising-temperature |
 
 ### UtilsClasses
 
diff --git a/Test.js b/Test.js
index 27850e4..f96160f 100644
--- a/Test.js
+++ b/Test.js
@@ -2,39 +2,64 @@
 /* eslint-disable no-undef */
 const fs = require("fs");
 
-const TESTS_FOLDER = "./LeetcodeProblemsTests/Algorithms/";
+const TESTS_FOLDERS = [
+  "./LeetcodeProblemsTests/Algorithms/easy/",
+  "./LeetcodeProblemsTests/Algorithms/medium/",
+  "./LeetcodeProblemsTests/Algorithms/hard/"
+]
+
 const REGEX_PATTERN_HIDDEN_FILES = /(^|\/)\.[^\/\.]/g;
 
 var test_all = async function () {
   try {
-    const problems = await loadProblems();
-    for (i in problems) {
-      console.log("Solving: " + problems[i]);
-      const tests = require(TESTS_FOLDER + problems[i]);  
-      if (Object.keys(tests).length == 0) {
-        console.warn("🔴 The problem " + problems[i] + " doesn't have a test method implemented.\n");
-        continue;
-      }
-      for(testIdx in tests) {
-        tests[testIdx]();
-      }
-      console.log("✅ Tests for " + problems[i] + " run successfully \n");
-    }
+    var problems = [];
+    for(const i in TESTS_FOLDERS) {
+      var folder = TESTS_FOLDERS[i];
+      var new_problems = await loadProblemsFiles(folder); // await
+      problems = problems.concat(new_problems);
+    };
+    console.log(problems);
+
+    var solvePromises = problems.map(solve);
+    
+    await Promise.all(solvePromises)
   } catch (error) {
+    console.log(error);
     throw new Error(error);
   }
 };
 
-var loadProblems = () => {
+var solve = (problem) => {
+  try {
+    console.log("Solving: " + problem);
+
+    const tests = require(problem);  
+    console.log("*" * 100);
+    if (Object.keys(tests).length == 0) {
+      console.warn("🔴 The problem " + problem + " doesn't have a test method implemented.\n");
+      return;
+    }
+    for(testIdx in tests) {
+      tests[testIdx]();
+    }
+    console.log("✅ Tests for " + problem + " run successfully \n");
+  } catch (error) {
+    console.log(error);
+    throw new Error(error);
+  }
+}
+
+var loadProblemsFiles = (folder) => {
   return new Promise(function (resolve, reject) {
-    fs.readdir(TESTS_FOLDER, (error, files) => {
+    fs.readdir(folder, (error, files) => {
       if (error) {
         reject(error);
       } else {
-        problems = files.filter(
-          (item) => !REGEX_PATTERN_HIDDEN_FILES.test(item)
-        );
-        resolve(problems);
+        console.log(folder);
+        new_problems = files.filter((item) => !REGEX_PATTERN_HIDDEN_FILES.test(item));
+        new_problems = new_problems.map((item) => folder + item);
+
+        resolve(new_problems);
       }
     });
   });

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