优先队列

#include <iostream>
#include <functional>
#include <queue>
using namespace std;
struct node
{
    friend bool operator<(node n1,node n2)
    {
        return n1.priority<n2.priority;
    }
    int priority;
    int value;
};
int main()
{
    const int len=5;
    int i;
    int a[len]={3,5,9,6,2};
    //优先队列中从大到小输出
    priority_queue<int>q1;
    for(i=0;i<len;i++)
        q1.push(a[i]);
    for(int i=0;i<len;i++)
    {
        cout<<q1.top();
        q1.pop();
    }
    cout<<endl;
    //优先队列中从小到大输出
    priority_queue<int,vector<int>,greater<int> >q2;
    for(i=0;i<len;i++)
        q2.push(a[i]);
    for(i=0;i<len;i++)
    {
        cout<<q2.top();
        q2.pop();
    }
    cout<<endl;
    //按照某个优先级输出,该代码中为priority值大的先输出
    priority_queue<node>q3;
    node b[len];
    b[0].priority=6;b[0].value=1;
    b[1].priority=9;b[1].value=5;
    b[2].priority=2;b[2].value=3;
    b[3].priority=8;b[3].value=2;
    b[4].priority=1;b[4].value=4;
    for(i=0;i<len;i++)
        q3.push(b[i]);
    cout<<"优先级"<<'\t'<<"值"<<endl;
    for(i=0;i<len;i++)
    {
        cout<<q3.top().priority<<'\t'<<q3.top().value<<endl;
        q3.pop();
    }
    return 0;
}