NYOJ 16 矩形嵌套

题目：矩形嵌套

import java.util.Scanner;public class Main {//深搜超时---TimeLimitExceeded -- --java2013-07-23 22:55:29static F f[];static int n,max;public static void main(String[] args) {Scanner input=new Scanner(System.in);int N=input.nextInt();while(N-->0){n=input.nextInt();max=0;f=new F[n];for(int i=0;i<n;i++){int x=input.nextInt();int y=input.nextInt();f[i]=new F(x,y);}for(int i=0;i<n;i++){f[i].ok=false;dfs(f[i].wide,f[i].high,1);f[i].ok=true;}System.out.println(max);}}private static void dfs(int wide, int high, int sum) {//递归深度搜索if(sum>max)//记录最大值max=sum;for(int i=0;i<n;i++){if(f[i].ok&&(f[i].wide<wide&&f[i].high<high||f[i].wide<high&&f[i].high<wide)){f[i].ok=false;dfs(f[i].wide,f[i].high,sum+1);f[i].ok=true;}}}}class F{//存储长和宽，以及是否被用过int wide,high;boolean ok=true;F(int wide,int high){this.wide=wide;this.high=high;}F(){}}

import java.util.Scanner;public class Main{//动态规划，Accepted 47MS 739java2013-07-23 23:39:06static int g[][],t[],n;public static void main(String[] args) {Scanner input=new Scanner(System.in);int N=input.nextInt();while(N-->0){n=input.nextInt();int a[]=new int[n];int b[]=new int[n];g=new int[n][n];t=new int[n];for(int i=0;i<n;i++){a[i]=input.nextInt();b[i]=input.nextInt();}for(int i=0;i<n;i++)            for(int j=0;j<n;j++)                if((a[i]>a[j]&&b[i]>b[j])||(a[i]>b[j]&&b[i]>a[j]))                     g[i][j]=1;int max=-1;for(int i=0;i<n;++i)            if(dp(i)>max)                max=dp(i);System.out.println(max);}}private static int dp(int i) {int ans=t[i];    if(ans>0)        return ans;    ans=1;    for(int j=0;j<n;++j)        if(g[i][j]!=0)            if(ans<dp(j)+1){                ans=dp(j)+1;                t[i]=ans;            }    return ans;}}