https://www.hackerrank.com/challenges/cpp-sets/problem #include #include #include #include #include #include using namespace std; int main() { set s; set::iterator itr; int num, q, val; cin >> num; for (int i = 0; i > q >> val; if (q == 1) s.insert(val); else if (q == 2) s.erase(val); else { itr = s.find(val); if (itr == s.end()) cout