关于优先队列浅析(priority_queue)

优先队列 greater与less,

自定义还有结构体(可以设置2层优先级)  模板;

下面废话不多说直接上程序  

注释的很明白

#include<iostream>
#include<cstring>
#include<algorithm>
#include<functional>
#define nn 100000005
#include<cstdio>
#include<queue>
using namespace std;
queue<int > q;
struct nood
{
    int a,b;
} p[nn],tmp;
bool operator<(nood x,nood y)
{
    return x.a>y.a;
}
/*
bool operator<(int a,int b)
{
return a>b;
}
priority_queue<int > qqq; 
//自定义 优先级 
*/
//  greater 小到大 less  大到小
//q.pop() 弹出最优元素 q.push()送入元素
//q.empty()判断队列是否为空
//q.size()  返回队列的长度
priority_queue<int,vector<int>,greater<int> > qq;
priority_queue<int,vector<int>,less<int> >qw;
int main()
{
    int a[4]= {16,6,8,1};

    for(int i=0; i<4; i++)
        qq.push(a[i]);

    for(int i=0; i<4; i++)
    {
        cout<<qq.top()<<endl;
        qq.pop();
    }

    for(int i=0; i<4; i++)
        qw.push(a[i]);
    cout<<endl;
    cout<<qw.size()<<endl;
    /*    for(int i=0; i<4; i++)
            {
                cout<<qw.top()<<endl;
                qw.pop();
             }                          */
cout<<endl;
while(!qw.empty())
{
    cout<<qw.top()<<endl;
    qw.pop();
}
cout<<endl<<qw.size()<<endl;

//结构体优先级排序
for(int i=0; i<5; i++)
    p[i].a=i;
priority_queue<nood> stru;
for(int i=0; i<5; i++)
    stru.push(p[i]);
cout<<endl;
cout<<stru.size()<<endl;
cout<<endl;
for(int i=0; i<5; i++)
{
    tmp=stru.top();
    cout<<tmp.a<<" ";
    stru.pop();
}
cout<<endl<<stru.size()<<endl;

/*priority_queue<nood,vector<nood>,greater<nood> > nod;
for(int i=0; i<5; i++)
    nod.push(p[i].a);
cout<<endl;
for(int i=0; i<5; i++)
    cout<<nod.top()<<" ";
cout<<nod.size()<<endl;
for(int i=0; i<5; i++)
    nod.pop();
cout<<endl<<nod.size()<<endl;*/
return 0;
}