c++优先级队列 priority queue

优先级队列分为最大值优先队列、最小值优先队列

优先级队列适配器：STL priority_queue

优先级队列一般用来开发特殊应用

代码：

#include<iostream>
using namespace std;
#include<queue>


void main81()
{
    priority_queue<int> p1;//默认情况是最大优先级队列
    priority_queue<int, vector<int>, less<int>> p2;//less是提前定义好的函数 相当于谓词
    priority_queue<int, vector<int>, greater<int>> p3;//最小值有限队列

    p1.push(33);
    p1.push(13);
    p1.push(55);
    p1.push(22);

    cout << "队头元素：" << p1.top() << endl;
    cout << "队列大小: " << p1.size() << endl;

    while (p1.size())
    {
        cout << p1.top() << " ";
        p1.pop();
    }
    cout << "测试 最小值优先级队列" << endl;
    p3.push(33);
    p3.push(13);
    p3.push(55);
    p3.push(22);

    cout << "最小值优先级队列 队头元素：" << p3.top() << endl;
    cout << "最小值优先级队列 队列大小: " << p3.size() << endl;

    while (p3.size())
    {
        cout << p3.top() << " ";
        p3.pop();
    }
}
int main()
{
    main81();


    system("pause");
    return 0;
}