Answer by rmn for Find duplicates between arrays

What you are looking for is just a set of the two arrays (set contains every element once at most). The solution in c++:

#include <set>int main () {    int a[] = { 1,2,3 };    int b[] = { 4,2,3 };    std::set<int> s(a, a+3);    s.insert(b, b+3);}