update 242

fishercoder1534 · fishercoder1534 · commit 5f7c51251dc3 · 2023-01-29T11:35:07.000-08:00
diff --git a/README.md b/README.md
@@ -9,7 +9,7 @@ _If you like this project, please leave me a star._ &#9733;
 | #    |      Title     | Solutions                                                                                                                                | Video                                                                         | Difficulty                       | Tag                  
 |------|----------------|------------------------------------------------------------------------------------------------------------------------------------------|-------------------------------------------------------------------------------|----------------------------------|-------------
 | 2549 |[Count Distinct Numbers on Board](https://leetcode.com/problems/count-distinct-numbers-on-board/)| [Java](../master/src/main/java/com/fishercoder/solutions/_2549.java)                                                                     || Easy                                                                          |
-| 2544 |[Alternating Digit Sum](https://leetcode.com/problems/alternating-digit-sum/)| [Java](../master/src/main/java/com/fishercoder/solutions/_2544.java)                                                                     |[:tv:](https://youtu.be/IFRYDmhEWGw)| Easy                                                                          |
+| 2544 |[Alternating Digit Sum](https://leetcode.com/problems/alternating-digit-sum/)| [Java](../master/src/main/java/com/fishercoder/solutions/_2544.java)                                                                     | [:tv:](https://youtu.be/IFRYDmhEWGw)                                          | Easy                                                                          |
 | 2540 |[Minimum Common Value](https://leetcode.com/problems/minimum-common-value/)| [Java](../master/src/main/java/com/fishercoder/solutions/_2540.java)                                                                     || Easy                                                                          |
 | 2536 |[Increment Submatrices by One](https://leetcode.com/problems/increment-submatrices-by-one/)| [Java](../master/src/main/java/com/fishercoder/solutions/_2536.java)                                                                     || Medium                                                                        |
 | 2535 |[Difference Between Element Sum and Digit Sum of an Array](https://leetcode.com/problems/difference-between-element-sum-and-digit-sum-of-an-array/)| [Java](../master/src/main/java/com/fishercoder/solutions/_2535.java)                                                                     || Easy                                                                          |
@@ -1169,7 +1169,7 @@ _If you like this project, please leave me a star._ &#9733;
 | 245  |[Shortest Word Distance III](https://leetcode.com/problems/shortest-word-distance-iii/)| [Solution](../master/src/main/java/com/fishercoder/solutions/_245.java)                                                                  |                                                                               | Medium                           | 
 | 244  |[Shortest Word Distance II](https://leetcode.com/problems/shortest-word-distance-ii/)| [Solution](../master/src/main/java/com/fishercoder/solutions/_244.java)                                                                  |                                                                               | Medium                           | HashMap
 | 243  |[Shortest Word Distance](https://leetcode.com/problems/shortest-word-distance/)| [Solution](../master/src/main/java/com/fishercoder/solutions/_243.java)                                                                  |                                                                               | Easy                             
-| 242  |[Valid Anagram](https://leetcode.com/problems/valid-anagram/)| [Solution](../master/src/main/java/com/fishercoder/solutions/_242.java)                                                                  |                                                                               | Easy                             
+| 242  |[Valid Anagram](https://leetcode.com/problems/valid-anagram/)| [Solution](../master/src/main/java/com/fishercoder/solutions/_242.java)                                                                  | [:tv:](https://youtu.be/7U3dMXiQBrU)                                                                      | Easy                             
 | 241  |[Different Ways to Add Parentheses](https://leetcode.com/problems/different-ways-to-add-parentheses/)| [Solution](../master/src/main/java/com/fishercoder/solutions/_241.java)                                                                  |                                                                               | Medium                           | Divide and Conquer
 | 240  |[Search a 2D Matrix II](https://leetcode.com/problems/search-a-2d-matrix-ii/)| [Solution](../master/src/main/java/com/fishercoder/solutions/_240.java)                                                                  |                                                                               | Medium                           | Binary Search
 | 239  |[Sliding Window Maximum](https://leetcode.com/problems/sliding-window-maximum/)| [Solution](../master/src/main/java/com/fishercoder/solutions/_239.java)                                                                  |                                                                               | Hard                             | Heap
diff --git a/src/main/java/com/fishercoder/solutions/_242.java b/src/main/java/com/fishercoder/solutions/_242.java
@@ -1,6 +1,8 @@
 package com.fishercoder.solutions;
 
 import java.util.Arrays;
+import java.util.HashMap;
+import java.util.Map;
 
 public class _242 {
 
@@ -32,4 +34,21 @@ public boolean isAnagram(String s, String t) {
             return true;
         }
     }
+
+    public static class Solution3 {
+        //to deal with unicode characters
+        public boolean isAnagram(String s, String t) {
+            Map<Character, Integer> map = new HashMap<>();
+            for (int i = 0; i < s.length(); i++) {
+                map.put(s.charAt(i), map.getOrDefault(s.charAt(i), 0) + 1);
+                map.put(t.charAt(i), map.getOrDefault(t.charAt(i), 0) - 1);
+            }
+            for (char c : map.keySet()) {
+                if (map.get(c) != 0) {
+                    return true;
+                }
+            }
+            return true;
+        }
+    }
 }
diff --git a/src/test/java/com/fishercoder/_242Test.java b/src/test/java/com/fishercoder/_242Test.java
@@ -0,0 +1,40 @@
+package com.fishercoder;
+
+import com.fishercoder.solutions._242;
+import org.junit.BeforeClass;
+import org.junit.Test;
+
+import static org.junit.Assert.assertEquals;
+
+public class _242Test {
+    private static _242.Solution1 solution1;
+    private static _242.Solution2 solution2;
+    private static _242.Solution3 solution3;
+    private static String s;
+    private static String t;
+
+    @BeforeClass
+    public static void setup() {
+        solution1 = new _242.Solution1();
+        solution2 = new _242.Solution2();
+        solution3 = new _242.Solution3();
+    }
+
+    @Test
+    public void test1() {
+        s = "anagram";
+        t = "nagaram";
+        assertEquals(true, solution1.isAnagram(s, t));
+        assertEquals(true, solution2.isAnagram(s, t));
+    }
+
+    @Test
+    public void test2() {
+        s = "代码写开心";
+        t = "开心写代码";
+        assertEquals(true, solution1.isAnagram(s, t));
+        //assertEquals(true, solution3.isAnagram(s, t));//solution2 won't work for unicode character input
+        assertEquals(true, solution3.isAnagram(s, t));
+    }
+
+}
