Figure 5.4, page 183

// A Hash routine for strings
// Polynomial function using Horner's rule


int hash ( const string & key, int tableSize )
{
    int hashVal = 0;

    // f(k) : string -> int
    for ( int i = 0; i < key.length(); i++ )
	hashVal = 37 * hashval + key [ i ];

    // g(k) : int -> {0, 1, 2, .... tableSize - 1}
    hashVal %= tableSize;

    // oops -- maybe overflow
    if ( hashVal < 0 )
	hashVal += tableSize;

    return hashVal;

}