feat: week02 valid-anagram

Author: std-freejia

valid-anagram/std-freejia.java

@@ -0,0 +1,14 @@
+class Solution {
+    public boolean isAnagram(String s, String t) {
+        if (s.length() != t.length()) return false;
+
+        Map<Character, Integer> mapS = new HashMap<>();
+        Map<Character, Integer> mapT = new HashMap<>();
+
+        for (int i = 0; i < s.length(); i++) {
+            mapS.put(s.charAt(i), mapS.getOrDefault(s.charAt(i), 0) + 1);
+            mapT.put(t.charAt(i), mapT.getOrDefault(t.charAt(i), 0) + 1);
+        }
+        return mapS.equals(mapT);
+    }
+}