Data structure for matching sets

Question

I have an application where I have a number of sets. A set might be
{4, 7, 12, 18}
unique numbers and all less than 50.

I then have several data items:
1 {1,

Answer 1

Since the numbers are less than 50, you could build a one-to-one hash using a 64-bit integer and then use bitwise operations to test the sets in O(1) time. The hash creation would also be O(1). I think either an XOR followed by a test for zero or an AND followed by a test for equality would work. (If I understood the problem correctly.)