CPP

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() << "
"; // 7
q.pop();
cout << q.top() << "
"; // 5
q.pop();
q.push(6);
cout << q.top() << "
"; // 6
q.pop();

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;

c++ priority_queue

priority_queue<int, vector<int>, greater<int> > gq

priority queue c++

priority_queue<int> pq;//this works like rank (e.g: rank=1 > rank=2)
//the lower the rank the higher is the priority
pq.push(3);
cout<<pq.top()<<endl;
cout<<pq.size()<<endl;
pq.pop();
if(pq.empty()){
  cout<<"priority queue is empty"<<endl;
}

priority_queue<int, vector<int>, greater<int>> pqr;
//this is the reverse priority queue
//this works like score the higher the score the more is it's priority
pqr.push(1);
pqr.push(4);
cout<<pqr.top()<<endl;
pqr.pop();
cout<<pqr.size()<<endl;
if(!pqr.empty()){
  cout<<"the priority queue is not empty"<<endl;
}

priority queue in cpp

// priority_queue::swap
#include <iostream>       // std::cout
#include <queue>          // std::priority_queue

int main ()
{
  std::priority_queue<int> foo,bar;
  foo.push (15); foo.push(30); foo.push(10);
  bar.push (101); bar.push(202);

  foo.swap(bar);

  std::cout << "size of foo: " << foo.size() << '
';
  std::cout << "size of bar: " << bar.size() << '
';

  return 0;
}