priority queue descending order c 2b 2b

1// using GCC 10.2 (C++2a) compiler
2#include <functional>
3#include <queue>
4#include <vector>
5#include <iostream>
6 
7template<typename T> void print_queue(T& q) {
8    while(!q.empty()) {
9        std::cout << q.top() << " ";
10        q.pop();
11    }
12    std::cout << '\n';
13}
14 
15int main() {
16    std::priority_queue<int> q;
17 
18    for(int n : {1,8,5,6,3,4,0,9,7,2})
19        q.push(n);
20 
21    print_queue(q);
22 
23    std::priority_queue<int, std::vector<int>, std::greater<int> > q2;
24 
25    for(int n : {1,8,5,6,3,4,0,9,7,2})
26        q2.push(n);
27 
28    print_queue(q2);
29 
30    // Using lambda to compare elements.
31    auto cmp = [](int left, int right) { return (left ^ 1) < (right ^ 1); };
32    std::priority_queue<int, std::vector<int>, decltype(cmp)> q3(cmp);
33 
34    for(int n : {1,8,5,6,3,4,0,9,7,2})
35        q3.push(n);
36 
37    print_queue(q3);
38 
39}
40

1The priority queue gquiz is :     30    20    10    5    1
2
3gquiz.size() : 5
4gquiz.top() : 30
5gquiz.pop() :     20    10    5    1
6