HDU 3974 Assign the task（并查集）

#include<cstdio>
#include<cstring>
#include<algorithm>
#include<vector>
#include<string>
#include<iostream>
#include<queue>
#include<cmath>
#include<map>
#include<stack>
#include<bitset>
using namespace std;
#define REPF( i , a , b ) for ( int i = a ; i <= b ; ++ i )
#define REP( i , n ) for ( int i = 0 ; i < n ; ++ i )
#define CLEAR( a , x ) memset ( a , x , sizeof a )
typedef long long LL;
typedef pair<int,int>pil;
const int maxn=50000+100;
struct node{
    int val;
    int time;
}e[maxn];
int pre[maxn];
int t,n,m;
int main()
{
    int x,y;
    int cas=1;
    char str[3];
    scanf("%d",&t);
    while(t--)
    {
        CLEAR(pre,-1);
        scanf("%d",&n);
        REPF(i,1,n)
        {
            e[i].val=-1;
            e[i].time=-1;
        }
        REPF(i,1,n-1)
        {
            scanf("%d%d",&x,&y);
            pre[x]=y;
        }
        scanf("%d",&m);
        int T=0;
        printf("Case #%d:\n",cas++);
        while(m--)
        {
            scanf("%s",str);
            if(str[0]=='T')
            {
                scanf("%d%d",&x,&y);
                e[x].val=y;
                e[x].time=++T;
            }
            else
            {
                scanf("%d",&x);
                int val=e[x].val;
                int time=e[x].time;
                while(x!=-1)
                {
                    if(e[x].time>time)
                    {
                        val=e[x].val;
                        time=e[x].time;
                    }
                    x=pre[x];
 //                   cout<<"fuck "<<endl;
                }
                printf("%d\n",val);
            }
        }
    }
    return 0;
}