The following is a collection of hash functions for integers.

Does not work too well with integers that are multiples of .

unsigned int TWHash(unsigned int a) {
    a = (a ^ 61) ^ (a >> 16);
    a = a + (a << 3);
    a = a ^ (a >> 4);
    a = a * 0x27d4eb2d;
    a = a ^ (a >> 15);
    return a;
}

private static int JavaHash(int h) {
    // This function ensures that hashCodes that differ only by
    // constant multiples at each bit position have a bounded
    // number of collisions (approximately 8 at default load factor).
    h ^= (h >> > 20) ^ (h >> > 12);
    return h ^ (h >> > 7) ^ (h >> > 4);
}