You can implement 0 prefix checking pretty easily in bitstrings: 0 == hash >> (hash_length - prefix_length) Or, alternatively: !(hash & prefix_mask)

You can implement 0 prefix checking pretty easily in bitstrings: 0 == hash >> (hash_length - prefix_length) Or, alternatively: !(hash & prefix_mask) where `prefix_mask` is 1111..000, with `prefix_length` number of 1s. I think that working in terms of bitstrings generated by the hash gives more context to why those integers are chosen (that they represent a certain portion of the space of possible answers), but it's also a matter of taste/background.