I really dislike posts like this one. For technical stuff like this people should start out with definition so everyone know what the author means by, for examp

I really dislike posts like this one. For technical stuff like this people should start out with definition so everyone know what the author means by, for example, "perfect hashing". > By implication, the hash must be at least as many bytes as the key and the function is theoretically reversible No. At least not by the standard definition[1]. In standard context, the problem of constructing a perfect hash function is, given (ahead of time) a list of items, you find a hash function that can map them to a smaller "range" without collision. [1] https://en.wikipedia.org/wiki/Perfect_hash_function https://en.wikipedia.org/wiki/Perfect_hash_function