hdu nyoj 220 推桌子

题目链接：http://acm.nyist.net/JudgeOnline/problem.php?pid=220

贪心算法

主要是除以二的那一点不好想，就是两排房子并行的

http://acm.nyist.net/JudgeOnline/problem.php?pid=220
#include<stdio.h>
#include<string.h>
#include<algorithm>
using namespace std;
struct node{
	int left;
	int right;
}table[300];
int cmp(node x,node y){
	return x.left<y.left;
}
int main(){
	int T;
	int N;
	int i,j,k,t;
	int mark[1000]; 
	int a,b,temp,ans;
	scanf("%d",&T);
	while(T--){
		scanf("%d",&N);
		memset(table,0,sizeof(table));
		memset(mark,0,sizeof(mark));
		for(i=0;i<N;i++)
		   {
		   	 scanf("%d%d",&a,&b);
		   	 a=(a+1)/2;
		   	 b=(b+1)/2;
		   	 table[i].left=a<b?a:b;
		   	 table[i].right=a<b?b:a;
		   }
		sort(table,table+N,cmp);
		ans=0;
		for(i=0;i<N;i++){
			if(!mark[i]){
				temp=table[i].right;
				mark[i]=1;
				ans++;
				for(j=i+1;j<N;j++){
					if(!mark[j]&&temp<table[j].left){
						temp=table[j].right;
						mark[j]=1;
					}
				}
			}
		}
		printf("%d\n",ans*10);
	}
	return 0;
}