矩形嵌套

题目分析：矩形嵌套，很水的DP，先按长（宽）递增排序，再按宽（长）二级排序，类似最长上升子序列，

dp[i]=max(dp[j])+1; 1<=j<i;

原题链接：http://acm.nyist.net/JudgeOnline/problem.php?pid=16

#include<iostream>#include<cstdio>#include<algorithm>using namespace std;struct node{ int a,b;}arr[1200];int dp[1200];int cmp(node x,node y){if(x.a==y.a)return x.b<y.b;elsereturn x.a<y.a;}int main(){int t;scanf("%d",&t);while(t--){int n,x,y;scanf("%d",&n);for(int i=1;i<=n;i++){scanf("%d %d",&x,&y);if(x>y){int temp=x;x=y;y=temp;}arr[i].a=x;arr[i].b=y;}sort(arr+1,arr+1+n,cmp);/*for(int i=1;i<=n;i++)printf("%d   %d\n",arr[i].a,arr[i].b);*/dp[1]=1;for(int i=2;i<=n;i++){int ans=0;for(int j=1;j<i;j++){if(arr[i].a!=arr[j].a && arr[i].b>arr[j].b&&dp[j]>ans)ans=dp[j];}dp[i]=ans+1;}int ans=0;/*for(int i=1;i<=n;i++)printf("%d  ",dp[i]);*///printf("\n");for(int i=1;i<=n;i++)if(dp[i]>ans)ans=dp[i];printf("%d\n",ans);}//system("pause");return 0;}