Hash table

A hash table is a data structure that can map keys to values using a hash function. It does this by computing an index using the hash function and stores the value in an array.

Operation Big-O
Access N/A
Search O(1)
Insert O(1)
Remove O(1)

To be clear, the O(1) is average case as it depends on the underlying hash function, but in most instances it is safe to assume average case.

References