Daniel-Constantin Mierla wrote:
just to be sure everyone got it right regarding the size attribute in htable parameter ... the number of slots for hash table is 2^size (2 power size). So, size=4 means that the hash table has 16 slots.
Reason for that is the speed in getting the slot number - modulo function is very fast in such cases, the slot number being actually a bitwise operation: hash_value & (2^size - 1) --- 2^size is cached at startup.
Thanks, that was a much-needed clarification omitted from my explanation.
I have always been told that table sizes that are prime numbers result in better distribution of factors due to the way modulo works, although I am not a mathematician and don't have a ready understanding of why. Is this true? Is there some reason you did not take this approach? Is hash_value & 2(^size - 1) equally fast?