I'm writing a mobile phone based game in c. I'm interested in a data structure that supports fast (amortized O(1) if possible) insertion, look-up, and removal. The data structure will store integers from the domain [0, n] where n is known ahead of time (it's a constant) and n is relatively small (on the order of 100000).

So far I've considered an array of integers where the "ith" bit is set iff the "ith" integer is contained in the set (so a[0] is integers 0 through 31, a[1] is integers 32 through 63 etc).

Is there an easier way to do this in c?