题意：给你三块玻璃，看能否拼成一整块正方形玻璃？

一共有四种情况，讨论即可

#include <iostream>
#include<bits/stdc++.h>
using namespace std;
struct node
{
    int x,y;
    bool operator <(const node& p)
    {
        if(x==p.x)
        {
            return y>p.y;
        }
        else return x>p.x;
    }
};
int main()
{
    node a[10];
    int sum =0;
    for(int i=0;i<=2;i++)
    {
        cin>>a[i].x>>a[i].y;
        if(a[i].x<a[i].y)
            swap(a[i].x,a[i].y);
         sum+=a[i].x*a[i].y;
    }
    sort(a,a+3);
    int r = (int )sqrt(sum);
    int f =0;
    if(r*r==sum)
    {
         if(a[0].x==r)
         {
             int p = r-a[0].y;
             if(a[1].x==a[2].x&&a[1].x==r&&p==a[1].y+a[2].y)f =1;
             if(a[1].x==a[2].x&&a[1].x==p&&a[1].y+a[2].y==r)f =1;
             if(a[1].y==a[2].y&&a[1].y==p&&a[1].x+a[2].x==r)f =1;
             if(a[1].x+a[2].y==r&&a[1].y==a[2].x&&a[1].y==p)f= 1;
         }

    }
    if(f)printf("YES\n");
    else printf("NO\n");

    return 0;
}