Algorithm to find if two sets intersect

Question

Let\'s say I have two arrays:

int ArrayA[] = {5, 17, 150, 230, 285};

int ArrayB[] = {7, 11, 57, 110, 230, 250};

Both arrays a

Answer 1

If the range of values is small, you could build a lookup table for one of them (time cost = O(N)) and then check if the bit is set from the other list (time cost = O(N)). If the range is large, you could do something similar with a hash table.

The mergesort trick from Glomek is an even better idea.