/**

* Calculate the number of positions at which the corresponding symbols are different.

*

* @author Atom

* @see <a href="https://en.wikipedia.org/wiki/Hamming_distance">Hamming distance</a>

*/

public class HammingDistance {

public static int hammingDistance(String s1, String s2) {

if (s1.length() != s2.length()) throw new IllegalArgumentException("The two strings must be the same length.");

int distance = 0;

for (int i = 0; i < s1.length(); i++) {

if (s1.charAt(i) != s2.charAt(i)) { distance++; }

}

return distance;

}

public static int hammingDistanceIgnoreCase(String s1, String s2) {

return hammingDistance(s1.toLowerCase(), s2.toLowerCase());

}

public static int hammingDistance(final int x, final int y) {

return Integer.bitCount(x ^ y);

}

public static int hammingDistance(final long x, final long y) {

return Long.bitCount(x ^ y);

}

public static void main(String[] args) {

System.out.println(hammingDistance("five", "five"));

System.out.println(hammingDistance("five", "four"));

System.out.println(hammingDistance("five", "FIVE"));

System.out.println(hammingDistanceIgnoreCase("five", "FIVE"));

System.out.println();

System.out.println(hammingDistance(1, 1));

System.out.println(hammingDistance(1, 2));

System.out.println(hammingDistance(1, 3));

System.out.println(hammingDistance(1, 4));

System.out.println(hammingDistance(1, 5));

System.out.println();

System.out.println(hammingDistance(1L, 1L));

System.out.println(hammingDistance(1L, 2L));

System.out.println(hammingDistance(1L, 3L));

System.out.println(hammingDistance(1L, 4L));

System.out.println(hammingDistance(1L, 5L));

}

}