Reverse a string in-space without an extra buffer. Complexity = O (n)

gistfile1.java

public static String reverse(String s) {
   int lenght = s.length();
   int last = s.length() - 1;
   char[] temp = s.toCharArray();
   for (int i = 0; i < lenght / 2; i++) {
      char c = temp[i];
      temp[i] = temp[last - i];
      temp[last - i] = c;
   }
   return new String(temp);
}