week2 valid-anagram solution commit

Author: f-exuan21

valid-anagram/f-euxan21.java

@@ -0,0 +1,27 @@
+// time : O(n)
+// space : O(n)
+
+class Solution {
+    public boolean isAnagram(String s, String t) {
+        char[] sToChar = s.toCharArray();
+        char[] tToChar = t.toCharArray();
+        
+        int[] charCount = new int[26];
+
+        for(char c : sToChar) {
+            charCount[c - 'a']++;
+        }
+
+        for(char c : tToChar) {
+            charCount[c - 'a']--;
+        }
+
+        for(int i : charCount) {
+            if(i != 0) {
+                return false;
+            }
+        }
+        
+        return true;
+    }
+}