关于priority_queue和sort()对结构体数组的排序

知乎的这个答案很清晰https://www.zhihu.com/question/35736022

#include <iostream>
#include <algorithm>
#include <stdio.h>
#include <cstring>
#include <queue>
using namespace std;
struct NODE
{
    int x,y;
    bool operator<(const NODE& p)const{
        if(x==p.x) return y>p.y;
        return x<p.x;
    }
}a[];
int main()
{
    int len=;
    a[len].x=, a[len++].y=;
    a[len].x=, a[len++].y=;
    a[len].x=, a[len++].y=;
    a[len].x=, a[len++].y=;
    sort(a,a+len);
    // 先按x升序排序 x相同时再按y降序排序
    printf("sort:\n");
    for(int i=;i<len;i++)
        printf("%d %d\n",a[i].x,a[i].y);
    printf("\n");
 
    priority_queue <NODE> q;
    // 先按x降序排序 x相同时再按y升序排序
    q.push((NODE){,});
    q.push((NODE){,});
    q.push((NODE){,});
    q.push((NODE){,});
    printf("优先队列：\n");
    while(!q.empty())
    {
        printf("%d %d\n",q.top().x,q.top().y);
        q.pop();
    }
    printf("\n");
 
    return ;
}