uva 1329

并查集路径压缩中，维护某节点到根节点的距离(依题意为abs(x-y)%1000)

即 d[i] +=d[father[i] ]

#include <iostream>
#include <algorithm>
#include <cmath>
using namespace std;
 const int N=1e5;
 int n,fa[N],d[N];
 
 int find(int x){
 	if(x==fa[x]) return x;
 	
 	int t=find(fa[x]);
 	d[x]+=d[fa[x]];
	fa[x]=t; 
	return t;
 }
 signed main(){
 	int cas,i,x,y;
 	char ch;
 	cin>>cas;
 	
 	while(cas--){
 		cin>>n;
 		for(i=1;i<=n;i++) fa[i]=i,d[i]=0;
 		while(cin>>ch&&ch!='O'){
 			if(ch=='I'){
 				cin>>x>>y; fa[x]=y; d[x]=abs(x-y)%1000;
			 }
			else{
				cin>>x; find(x); cout<<d[x]<<endl;
			}
		 }
	 }
 }