void test(priority_queue &pq) { pq.push(make_pair(1,1)); pq.push(make_pair(2,0)); pq.push(make_pair(0,2)); cout << pq.top().second << endl; pq.decrease_key(1,0); cout << pq.top().second << endl; pq.pop(); cout << pq.top().second << endl; pq.pop(); cout << pq.top().second << endl; }