优先队列

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

struct cmp1   //小到大
{
    bool operator () (int &a, int &b)
    {
        return a>b;
    }
};

struct cmp2   //大到小
{
    bool operator () (int &a, int &b)
    {
        return a<b;
    }
};

struct num1
{
    int x;
    bool operator < (const num1 a) const
    {
        return x>a.x;
    }
};

struct num2
{
    int x;
    bool operator < (const num2 a) const
    {
        return x<a.x;
    }
};

int main()
{
    priority_queue<int,vector<int>, cmp1> q1;
    priority_queue<int,vector<int>, cmp2> q2;
    priority_queue<num1> q3;
    priority_queue<num2> q4;

    int n;
    while(scanf("%d", &n)==1)
    {
        int x;
        num1 x1;
        num2 x2;
        for(int i=0; i<n; i++)
        {
            scanf("%d", &x);
            x1.x=x;
            x2.x=x;
            q1.push(x);
            q2.push(x);
            q3.push(x1);
            q4.push(x2);
        }

        while(!q1.empty())
        {
            printf("%d ", q1.top());
            q1.pop();
        }
        puts("");

        while(!q2.empty())
        {
            printf("%d ", q2.top());
            q2.pop();
        }
        puts("");

        while(!q3.empty())
        {
            printf("%d ", q3.top().x);
            q3.pop();
        }
        puts("");

        while(!q4.empty())
        {
            printf("%d ", q4.top().x);
            q4.pop();
        }
        puts("");
    }
    return 0;
}