C++ priority_queue - push() Function

The C++ priority_queue::push function is used to add a new element in the priority_queue. Each insertion of element increases the priority_queue container size by one.

priority_queue is similar to a heap, where elements can be inserted in any order and max heap element is retrieved first. Adding a new element effectively calls push_back of the underlying container, and then reorders the new element to its location in the heap by calling the push_heap algorithm on the range including all the elements of the container.

Syntax

• C++98
• C++11

void push (const value_type& val);

void push (const value_type& val);
void push (value_type&& val);

Parameters

Return Value

None.

Time Complexity

Logarithmic i.e, Θ(log(n)).

Example:

In the example below, the priority_queue::push function is used to add new elements in the priority_queue called pqueue.

#include <iostream>
#include <queue>
using namespace std;
 
int main (){
  priority_queue<int> pqueue;

  //add new elements in the priority_queue
  pqueue.push(100);
  pqueue.push(80);
  pqueue.push(990);
  pqueue.push(85);
  pqueue.push(10);


  cout<<"pqueue contains:";
  while (!pqueue.empty()) {
    cout<<" "<<pqueue.top();
    pqueue.pop();
  }
  return 0;
}

The output of the above code will be:

pqueue contains: 990 100 85 80 10