1.1

1.1

public static boolean isUniqueChars(String str) {

        boolean[] charset = new boolean[256];

        for (int i = 0; i < str.length(); i++) {

            int val = str.charAt(i);



            if (charset[val]) {

                return false;

            }



            charset[val] = true;

        }



        return true;

    }