【动态规划】矩形嵌套

#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>

using namespace std;

typedef struct node{
    int x;
    int y;
};
node juxing[1005];

int cmp(node a,node b){
    return a.x<b.x || a.x==b.x&&a.y<b.y;
}

int main()
{
    int N;
    int n;
    int ans;
    int maxx;
    int sum[1005];
    scanf("%d",&N);
    while(N--){
        scanf("%d",&n);
        for(int i=0;i<n;i++){
            scanf("%d %d",&juxing[i].x,&juxing[i].y);
            if(juxing[i].x<juxing[i].y){
                int temp=juxing[i].x;
                juxing[i].x=juxing[i].y;
                juxing[i].y=temp;
            }
            sum[i]=1;
        }
        sort(juxing,juxing+n,cmp);
        maxx=1;
        for(int i=1;i<n;i++){
            ans=0;
            for(int j=0;j<i;j++){
                if(juxing[j].x<juxing[i].x&&juxing[j].y<juxing[i].y){
                    ans=max(sum[j],ans);
                }
            }
            sum[i]=ans+1;
            maxx=max(sum[i],maxx);
        }
        printf("%d\n",maxx);
    }
    return 0;
}