add 445

fishercoder1534 · fishercoder1534 · commit ed4827e56aa1 · 2017-05-13T11:56:46.000-07:00
diff --git a/README.md b/README.md
@@ -98,7 +98,7 @@ Your ideas/fixes/algorithms are more than welcome!
 |449|[Serialize and Deserialize BST](https://leetcode.com/problems/serialize-and-deserialize-bst/)|[Solution](../master/src/main/java/com/stevesun/solutions/SerializeandDeserializeBST.java)| O(n)|O(h) | Medium| BFS
 |448|[Find All Numbers Disappeared in an Array](https://leetcode.com/problems/find-all-numbers-disappeared-in-an-array/)|[Solution](../master/src/main/java/com/stevesun/solutions/FindAllNumbersDisappearedinanArray.java)| O(n)|O(1) | Easy| Array, HashMap
 |447|[Number of Boomerangs](https://leetcode.com/problems/number-of-boomerangs/)|[Solution](../master/src/main/java/com/stevesun/solutions/NumberofBoomerangs.java)| O(n^2)|O(n) | Easy| HashMap
-|445|[Add Two Numbers II](https://leetcode.com/problems/add-two-numbers-ii/)|[Solution](../master/src/main/java/com/stevesun/solutions/AddTwoNumbersII.java)| O(max(m,n)|O(max(m,n)) | Medium| Stack
+|445|[Add Two Numbers II](https://leetcode.com/problems/add-two-numbers-ii/)|[Solution](../master/src/main/java/com/stevesun/solutions/_445.java)| O(max(m,n)|O(max(m,n)) | Medium| Stack, LinkedList
 |442|[Find All Duplicates in an Array](https://leetcode.com/problems/find-all-duplicates-in-an-array/)|[Solution](../master/src/main/java/com/stevesun/solutions/FindAllDuplicatesinanArray.java)| O(n)|O(1) | Medium| Array
 |441|[Arranging Coins](https://leetcode.com/problems/arrange-coins/)|[Solution](../master/src/main/java/com/stevesun/solutions/ArrangingCoins.java)| O(n)|O(1) | Easy|
 |438|[Find All Anagrams in a String](https://leetcode.com/problems/find-all-anagrams-in-a-string/)|[Solution](../master/src/main/java/com/stevesun/solutions/FindAllAnagramsinaString.java)| O(n)|O(1) | Easy|
diff --git a/src/main/java/com/stevesun/solutions/_445.java b/src/main/java/com/stevesun/solutions/_445.java
@@ -2,6 +2,8 @@
 
 import com.stevesun.common.classes.ListNode;
 
+import java.util.ArrayDeque;
+import java.util.Deque;
 import java.util.Stack;
 
 /**
@@ -17,17 +19,17 @@
  Input: (7 -> 2 -> 4 -> 3) + (5 -> 6 -> 4)
  Output: 7 -> 8 -> 0 -> 7
  */
-public class AddTwoNumbersII {
+public class _445 {
 
     public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
-        Stack<Integer> stack1 = popIntoStack(l1);
-        Stack<Integer> stack2 = popIntoStack(l2);
+        Deque<Integer> stack1 = popIntoStack(l1);
+        Deque<Integer> stack2 = popIntoStack(l2);
 
         int sum = 0;
         ListNode list = new ListNode(0);
         while (!stack1.isEmpty() || !stack2.isEmpty()) {
-            if (!stack1.isEmpty()) sum += stack1.pop();
-            if (!stack2.isEmpty()) sum += stack2.pop();
+            if (!stack1.isEmpty()) sum += stack1.removeFirst();
+            if (!stack2.isEmpty()) sum += stack2.removeFirst();
             list.val = sum % 10;
             ListNode head = new ListNode(sum / 10);
             head.next = list;
@@ -37,9 +39,9 @@ public ListNode addTwoNumbers(ListNode l1, ListNode l2) {
         return list.val == 0 ? list.next : list;
     }
 
-    private Stack<Integer> popIntoStack(ListNode head) {
+    private Deque<Integer> popIntoStack(ListNode head) {
         ListNode tmp = head;
-        Stack<Integer> stack = new Stack<>();
+        Deque<Integer> stack = new ArrayDeque<>();
         while (tmp != null) {
             stack.push(tmp.val);
             tmp = tmp.next;
diff --git a/src/test/java/com/stevesun/_445Test.java b/src/test/java/com/stevesun/_445Test.java
@@ -0,0 +1,39 @@
+package com.stevesun;
+
+import com.stevesun.common.classes.ListNode;
+import com.stevesun.solutions._171;
+import com.stevesun.solutions._445;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+/**
+ * Created by stevesun on 5/13/17.
+ */
+public class _445Test {
+    private static _445 test;
+
+    @BeforeClass
+    public static void setup(){
+        test = new _445();
+    }
+
+    @Test
+    public void test1(){
+        ListNode l1 = new ListNode(7);
+        l1.next = new ListNode(2);
+        l1.next.next = new ListNode(4);
+        l1.next.next.next = new ListNode(3);
+
+        ListNode l2 = new ListNode(5);
+        l2.next = new ListNode(6);
+        l2.next.next = new ListNode(4);
+
+        ListNode expected = new ListNode(7);
+        expected.next = new ListNode(8);
+        expected.next.next = new ListNode(0);
+        expected.next.next.next = new ListNode(7);
+        assertEquals(expected, test.addTwoNumbers(l1, l2));
+    }
+}
