priority_queue () large and small root root heap heap (binary heap)

#include <the iostream> 
#include <Queue>
 the using  namespace STD;
 int main () 
{ 
    // for a base type default heap big top 
    The priority_queue < int > A; 
     // equivalent priority_queue <int, vector <int> , less < int>> A; 
    
    //              there must be a space, or become a right-shift operator ↓ 
    The priority_queue < int , Vector < int >, Greater < int >> C;   // this is a small top stack 
    The priority_queue < String > B; 

    for ( int I = 0 ; I < . 5 ; I ++) 
    {
        a.push(i);
        c.push(i);
    }
    while (!a.empty()) 
    {
        cout << a.top() << ' ';
        a.pop();
    } 
    cout << endl;

    while (!c.empty()) 
    {
        cout << c.top() << ' ';
        c.pop();
    }
    cout << endl;

    b.push("abc");
    b.push("abcd");
    b.push("cbd");
    while (!b.empty()) 
    {
        cout << b.top() << ' ';
        b.pop();
    } 
    cout << endl;
    return 0;
}

Essence heap priority queue implementation;

The default definition of a large root heap priority queue, i.e. the value of the parent node is greater than the value of the child node.

The priority_queue <int> A; 
    // equivalent priority_queue <int, vector <int> , less <int>> a; 
of course also be defined rootlets stack:

priority_queue <int, vector <int>, greater <int>> c; // this is a small stack top

The pair is added to the queue: 
The priority_queue <pair <int, int>> A; // first comparator then compare the first second 

operation with respect to the priority queue;

Access top the head elements 
if the queue is empty empty 
return the number of elements within a queue size 
Push element is inserted into the tail (and ordering) 
emplace situ element and configured to enqueue a 
pop pop head elements 
swap exchanging content

Can join behind from the queue, the queue out of the front, at the time of traversal by P.SIZE () or p.empty (); 
excerpt from the blog from https://blog.csdn.net/weixin_36888577/article/details / 79937886