Hashing functions are functions from some set of keys for data items
to memory locations where these items can (should) be stored.
E.g. data items - student records, keys - their SSNs.
A popular hashing function h is
where k is a key and m is the number of memory locations.
Example. If there are 1000 locations, at what location would be the
record for the student whose SSN is 315-17-4251 ?
Why would it be a bad idea to hash by the first (rather than last) 3
--- We would likely have many collisions.