Hash functions for Speller CS50

SAMPLE HASH FUNCTIONS for SPELLER
----------------------

// Hashes word to a number
unsigned int hash(const char *word)
{
     // djb2 hash function source:http://www.cse.yorku.ca/~oz/hash.html

     unsigned long x = 5381;

     while (*word)
     {
         x += (x << 5) + tolower(*word);
         word++;
     }

     return x % N;
}

-------------------------------

// Hashes word to a number
unsigned int hash(const char *word)
{

    unsigned int hashing = 3581;
    for (int i = 0, n = strlen(word); i < n; i++)
    {
        hashing = (hashing << 2) ^ tolower(word[i]);
    }
    return hashing % N;

}

----------------------------------------------------

unsigned int hash(const char *word)
{
    // 32-bit MurmurHash

    unsigned int h = 3323198485;
    while (*word)
    {
        h ^= tolower(*word);
        h *= 0x5bd1e995;
        h ^= h >> 15;
        word++;
    }
    return h % N;
}

-------------------------------

// Hashes word to a number
unsigned int hash(const char *word)
{
    // String Folding  source: https://opendsa-server.cs.vt.edu/

    unsigned int sum = 0;
    long factor = 1;
    int length = strlen(word);

    for (int i = 0; i < length; i++)
    {
        factor = i % 4 == 0 ? 1 : factor << 8;
        sum += tolower(word[i]) * factor;
    }
    return sum % N;
}