hdu3729 I'm Telling the Truth (最大匹配)

题目链接：http://acm.hdu.edu.cn/showproblem.php?pid=3729

题解：见http://blog.youkuaiyun.com/zizaimengzhongyue/article/details/8980736

http://blog.sina.com.cn/s/blog_6ec5c2d00100vrm6.html

#include <stdio.h>
#include <string.h>
#define MAXN 100002

struct node
{
	int x,y;
}rank[62];

int from[MAXN],used[MAXN],to[62];

int match(int x)
{
	int i;
	for(i=rank[x].x;i<=rank[x].y;++i)
	{
		if(!used[i])
		{
			used[i]=1;
			if(from[i]==-1||match(from[i]))
			{
				from[i]=x;
				to[x]=1;
				return 1;
			}
		}
	}
	return 0;
}

int hungary(int n)
{
	int i,sum=0;
	memset(from,-1,sizeof(from));
	memset(to,0,sizeof(to));
	for(i=n;i>=1;--i)
	{
		memset(used,0,sizeof(used));
		if(match(i))
			sum++;
	}
	return sum;
}

int main()
{
	int i,n,ans,test,cnt;
	scanf("%d",&test);
	while(test--)
	{
		scanf("%d",&n);
		for(i=1;i<=n;++i)
			scanf("%d %d",&rank[i].x,&rank[i].y);
		ans=hungary(n);
		printf("%d\n",ans);
		for(i=1;i<=n-1;++i)
		{
			if(to[i])
				printf("%d ",i);
		}
		printf("%d\n",i);
	}
	return 0;
}