// prqueue.cpp: A priority queue; a demonstration of the
// member function push, pop, empty, and top.
#include <iostream>
#include <vector>
#include <functional>
#include <queue>
using namespace std;

int main() {
 priority_queue <int, vector<int>, greater<int> > P;
 int x;
 P.push(123); P.push(51); P.push(1000); P.push(17);
 while (!P.empty()) {
 x = P.top();
 cout << "Retrived element: " << x << endl;
 P.pop();
 }
 return 0;
}