priority queue c++

                                    // using GCC 10.2 (C++2a) compiler
#include <functional>
#include <queue>
#include <vector>
#include <iostream>
 
template<typename T> void print_queue(T& q) {
    while(!q.empty()) {
        std::cout << q.top() << " ";
        q.pop();
    }
    std::cout << '\n';
}
 
int main() {
    std::priority_queue<int> q;
 
    for(int n : {1,8,5,6,3,4,0,9,7,2})
        q.push(n);
 
    print_queue(q);
 
    std::priority_queue<int, std::vector<int>, std::greater<int> > q2;
 
    for(int n : {1,8,5,6,3,4,0,9,7,2})
        q2.push(n);
 
    print_queue(q2);
 
    // Using lambda to compare elements.
    auto cmp = [](int left, int right) { return (left ^ 1) < (right ^ 1); };
    std::priority_queue<int, std::vector<int>, decltype(cmp)> q3(cmp);
 
    for(int n : {1,8,5,6,3,4,0,9,7,2})
        q3.push(n);
 
    print_queue(q3);
 
}

                                    //Shubh'grepper
// Implementation of priority_queue in c++

//queue with elements in decreasing order
priority_queue<int> pq;

// queue with elements in increasing order  using compare function inside declaration
priority_queue <int, vector<int>, greater<int> > pq;

//priority_queue of type pair<int, int>
#define pp pair<int, int>
priority_queue <pp, vector<pp>, greater<pp> > pq;

                                    // Implementation of priority_queue in c++

//queue with elements in decreasing order
priority_queue<int> pq;

// queue with elements in increasing order  using compare function inside declaration
priority_queue <int, vector<int>, greater<int> > pq;

//priority_queue of type pair<int, int>
#define pp pair<int, int>
priority_queue <pp, vector<pp>, greater<pp> > pq;

                                    /* A priority queue maintains a set of elements. The supported operations are
insertion and, depending on the type of the queue, retrieval and removal 
of either the minimum or maximum element. Insertion and removal take 
O(logn) time, and retrieval takes O(1) time. */
priority_queue<int> q;
q.push(3); // 3
q.push(5); // 3 5
q.push(7); // 3 5 7
q.push(2); // 2 3 5 7
cout << q.top() << "\n"; // 7
q.pop();
cout << q.top() << "\n"; // 5
q.pop();
q.push(6);
cout << q.top() << "\n"; // 6
q.pop();

                                    #include<iostream>
#include<queue>
#include<algorithm>

using namespace std;

int main()
{
    priority_queue<int>pq;
    int n=5;
    while(n--)
    {
        int val;
        cout<<"enter the value you want to insert:"<<endl;
        cin>>val;
        pq.push(val);
    }
    priority_queue<int>p;
    p.push(100);
    p.push(1000);
    p.push(3000);
    p.push(5000);
    pq.swap(p);
    while(!pq.empty())
    {
        cout<<pq.top()<<" ";
        pq.pop();
    }
    return 0;
}