Answers for "priority queue stl"

priority queue c++

/* 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();

priority queue cpp

// 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);
 
}

priority queue in c++

//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;

priority_queue

std::priority_queue<int, std::vector<int>, std::greater<int>>

priority queue stl

#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;
}

priority queue

function PriorityQueue() {
  this.collection = [];
  this.printCollection = function () {
    console.log(this.collection);
  };
  // Only change code below this line
  this.enqueue = function (newitem) {
    if (this.isEmpty()) {
      return this.collection.push(newitem);
    }

    this.collection = this.collection.reverse();
    var found_index = this.collection.findIndex(function (item) {
      return newitem[1] >= item[1];
    });
    if (found_index === -1) {
      this.collection.push(newitem);
    } else {
      this.collection.splice(found_index, 0, newitem);
    }
    this.collection = this.collection.reverse();
  };
  this.dequeue = function () {
    if (!this.isEmpty()) {
      return this.collection.shift()[0];
    } else {
      return "The queue is empty.";
    }
  };
  this.size = function () {
    return this.collection.length;
  };
  this.front = function () {
    return this.collection[0][0];
  };
  this.isEmpty = function () {
    return this.size() > 0 ? false : true;
  };
  // Only change code above this line
}