feat: add valid anagram

Author: heozeop

valid-anagram/heozeop.cpp

@@ -0,0 +1,26 @@
+// Time Complexity: O(n)
+// Spatial Complexity: O(1)
+
+class Solution {
+public:
+    bool isAnagram(string s, string t) {
+        int numberOfAlphabet[26];
+
+        for(char character : s) {
+            numberOfAlphabet[character - 'a']++;
+        }
+
+        for(char character : t) {
+            numberOfAlphabet[character - 'a']--;
+        }
+
+        for(int i = 0; i < 26; ++i) {
+            if (numberOfAlphabet[i] != 0) {
+                return false;
+            }
+        }
+        
+        return true;
+    }
+};
+