max heap using priority queue code example

Example 1: max heap java

import java.util.PriorityQueue;

public class MaxHeapWithPriorityQueue {

    public static void main(String args[]) {
        // create priority queue
        PriorityQueue<Integer> prq = new PriorityQueue<>(Comparator.reverseOrder());

        // insert values in the queue
        prq.add(6);
        prq.add(9);
        prq.add(5);
        prq.add(64);
        prq.add(6);

        //print values
        while (!prq.isEmpty()) {
            System.out.print(prq.poll()+" ");
        }
    }

}

Example 2: min heap priority queue c++

#include<queue>
std::priority_queue <int, std::vector<int>, std::greater<int> > minHeap;

Example 3: priority queue max heap in java

//Sol1
PriorityQueue<Integer> queue = new PriorityQueue<>(10, Collections.reverseOrder());


//Sol2
// PriorityQueue<Integer> pq = new PriorityQueue<>((x, y) -> y - x);
PriorityQueue<Integer> pq =new PriorityQueue<>((x, y) -> Integer.compare(y, x));


//Sol3
PriorityQueue<Integer> pq = new PriorityQueue<Integer>(defaultSize, new Comparator<Integer>() {
    public int compare(Integer lhs, Integer rhs) {
        if (lhs < rhs) return +1;
        if (lhs.equals(rhs)) return 0;
        return -1;
    }
});

Example 4: Priority Queue using Min Heap in c++

#include <bits/stdc++.h>
using namespace std;
 

int main ()
{
   
    priority_queue <int> pq;
    pq.push(5);
    pq.push(1);
    pq.push(10);
    pq.push(30);
    pq.push(20);
 
   
    while (pq.empty() == false)
    {
        cout << pq.top() << " ";
        pq.pop();
    }
 
    return 0;
}