并查集的扩展应用，求节点到根的距离

//求节点到根的距离
//r[i]存储节点 i 到根的距离#include <stdio.h>
#include <iostream>
#include <string.h>
#include <algorithm>
#include <stdlib.h>using namespace std;int p[100010];
int r[100010];int findd (int x)
{int ans=0;while (x != p[x]){ans++;x=p[x];}return ans;
}void un(int a ,int b)
{p[b]=a;
}int main ()
{int n,m;int b,c;while (scanf ("%d%d",&n,&m)!=EOF){if (n==0 && m==0)break;for (int i =0;i<=n;i++){p[i]=i;r[i]=0;}for (int i =1;i<n;i++){scanf ("%d%d",&b,&c);un(b,c);}for (int i =1;i<=m;i++){scanf("%d %d",&b,&c);int t1=findd(b);int t2=findd(c);if (t1 <= t2)printf("lxh\n");elseprintf("pfz\n");}}return 0;
}