C :

#include<stdio.h>
#include<stdlib.h>
#include<string.h>
#include<math.h>
#define N 1010
struct Node
{
    double l;
    double w;

}node[N];

int cmp(const void *a,const void *b)
{
    if((*(struct Node *)a).l!=(*(struct Node *)b).l)
      return (*(struct Node *)a).l > (*(struct Node *)b).l ?1:-1;
    else
      return (*(struct Node *)a).w > (*(struct Node *)b).w ?1:-1;
}
int main()
{
    int ncase;
    scanf("%d",&ncase);
    while(ncase--)
    {
		int n,i,j;
		double t;
        int count=1;
        scanf("%d",&n);
        for(i=0;i<n;i++)
        {
            scanf("%lf%lf",&node[i].w,&node[i].l);
			if(node[i].w>node[i].l)
			{
				t=node[i].w;
				node[i].w=node[i].l;
				node[i].l=t;
			}
		}       
        qsort(node,n,sizeof(node[0]),cmp);
        for(i=0;i<n-1;)
		{
			for(j=i+1;j<n;)
			{
				if(node[i].l<node[j].l && node[i].w<node[j].w)
				{
					count++;
					i=j;
					break;
				}
				else
					j++;
			}
			if(j==n)
				break;
		}
		printf("%d\n",count);
    }
    return 0;
}

C++ :

#include<cstdio>
#include<algorithm>
#include<cstring>
#define M 1024
using namespace std;
struct rect{
    int len,width;
}d[M],p[M];
bool cmp(rect a,rect b)//按长排降序，后再按宽排
{
    if(a.len==b.len) return a.width<b.width;
    return a.len>b.len;
}
int main(){
    int m;
    scanf("%d",&m);
    while(m--)
    {
        int n,i,j,t;
        scanf("%d",&n);
        for(i=0;i<n;i++){
            scanf("%d %d",&d[i].len,&d[i].width);
            if(d[i].width>d[i].len)
                {
                    t=d[i].width;
                    d[i].width=d[i].len;
                    d[i].len=t;
                }
           }
        sort(d,d+n,cmp);
        int length=1;
        p[0].len=900,p[0].width=900;
        for(i=0;i<n;i++)//终止位置
        {
            for(j=length-1;j>=0;j--)//length 长度
             {
                 if(d[i].width<p[j].width&&d[i].len<p[j].len) { p[j+1]=d[i];  if(j+1==length) length++; break;}

             }
        }
        printf("%d\n",length-1);
        }
}

Java :

import java.util.Scanner;



public class Main {
	public static void main(String[] args) {
		Scanner in = new Scanner(System.in);
		int t = in.nextInt();
		while (t-- > 0) {
			int n = in.nextInt();
			Graph[] map = new Graph[100];
			int[] f = new int[n + 1];
			boolean[][] g = new boolean[100][100];
			for (int i = 1; i <= n; i++) {
				map[i] = new Graph();
				map[i].x = in.nextInt();
				map[i].y = in.nextInt();
			}
			for (int i = 1; i <= n; i++) {
				for (int j = 1; j <= n; j++) {
					if (map[i].x < map[j].x && map[i].y < map[j].y
							|| map[i].x < map[j].y && map[i].y < map[j].x)
						g[i][j] = true;
				}
			}
			for (int i = 1; i <= n; i++) {
				f[i] = dp(f, i, n, g);
			}
			int max = 0;
			for (int i = 1; i <= n; i++) {
				if (max < f[i]) {
					max = f[i];
				}
			}
			System.out.println(max);
		}
	}

	public static int dp(int[] f, int i, int n, boolean[][] g) {
		if (f[i] > 0)
			return f[i];
		f[i] = 1;
		for (int j = 1; j <= n; j++) {
			if (g[i][j])
				f[i] = Math.max(f[i], dp(f,j,n,g) + 1);
		}
		return f[i];
	}
}
class Graph{
	int x,y;
}