hdu2545 树上战争

#include <stdio.h>
//谁离根节点进谁就胜
int father[100002];

int find(int x)
{
	int sum=0;
	while(x!=father[x])
	{
		x=father[x];
		sum++;
	}
	return sum;
}

int main()
{
	int n,m,i,x,y;
	while(scanf("%d %d",&n,&m)&&n)
	{
		for(i=1;i<=n;i++)
			father[i]=i;
		for(i=1;i<n;i++)
		{
			scanf("%d %d",&x,&y);
			father[y]=x;
		}
		while(m--)
		{
			scanf("%d %d",&x,&y);
			if(find(x)<=find(y))
				printf("lxh\n");
			else
				printf("pfz\n");
		}
	}
	return 0;
}