Algorithm to check if the given 2 strings are anagram. Complexity = O (n)

gistfile1.java

public static boolean checkIfAnagram(String s1, String s2) {
   int len1 = s1.length();
   for (int i = 0; i < len1; i++) {
      if (s1.charAt(i) != s2.charAt(len1 - i - 1)) {
         return false;
      }
   }
   return true;
}