Hashtable/Map: where to start

Question

I am looking to make a function that takes a string and returns a value that is in an dynamic's array range, basically, a dynamic hash-table, But I'm rather confused on where to start, I have the vector down, but I don't know which hashing function would be good for perhaps runtime performance -- I want it to be fast and with no collisions, therefore, I would love if you could share some resources on candidate implementations or algorithms

Thank you.

Answer 1

Well, there is alot of factors to have in consideration. One is the size of the hash table. A hash table is only good if there is no colisions so a big prime number will do, however if the number is to big u will waste alot of memory, you have to take in consideration how much data you are expecting. Same case happens if your prime is to low, u are force to create remake the hash.

There is 2 solution that im aware of to prevent the colisions: U can create another hash or array list inside of your hash everytime a collision happens.

Or u can also everytime a colision happen try to put that info in the next free space of your hash table.