PKU1988磁铁

Cube Stacking

Time Limit: 2000MS		Memory Limit: 30000K
Total Submissions: 16258		Accepted: 5579
Case Time Limit: 1000MS

Description

Farmer John and Betsy are playing a game with N (1 <= N <= 30,000)identical cubes labeled 1 through N. They start with N stacks, each containing a single cube. Farmer John asks Betsy to perform P (1<= P <= 100,000) operation. There are two types of operations:  moves and counts.  * In a move operation, Farmer John asks Bessie to move the stack containing cube X on top of the stack containing cube Y.  * In a count operation, Farmer John asks Bessie to count the number of cubes on the stack with cube X that are under the cube X and report that value. 
Write a program that can verify the results of the game. 

Input

* Line 1: A single integer, P 
* Lines 2..P+1: Each of these lines describes a legal operation. Line 2 describes the first operation, etc. Each line begins with a 'M' for a move operation or a 'C' for a count operation. For move operations, the line also contains two integers: X and Y.For count operations, the line also contains a single integer: X. 
Note that the value for N does not appear in the input file. No move operation will request a move a stack onto itself. 

Output

Print the output from each of the count operations in the same order as the input file. 

Sample Input

6
M 1 6
C 1
M 2 4
M 2 6
C 3
C 4

Sample Output

1
0
2

Source

USACO 2004 U S Open

#include <iostream>
#include<stdio.h>
using namespace std;
#define maxn 30003
int num[maxn];
int dis[maxn]={0};
int father[maxn];
int find_set(int x)
{
    if(x!=father[x])
    {
        int temp=father[x];
        father[x]=find_set(father[x]);
        dis[x]+=dis[temp];
    }
    return father[x];
}
void union_set(int a,int b)
{
    int fathera=find_set(a);
    int fatherb=find_set(b);
    father[fatherb]=fathera;
    dis[fatherb]=num[fathera];
    num[fathera]+=num[fatherb];
}
int main()
{
    int n;
    char ch[2];
    int a,b;
    scanf("%d",&n);
    int i;
    for(i=0;i<maxn;i++)
    {
        father[i]=i;
        num[i]=1;
    }
    while(n--)
    {
        scanf("%s%d",&ch,&a);
        if(ch[0]=='M')
        {
            scanf("%d",&b);
            union_set(a,b);
        }
        else
        {
            int temp=find_set(a);
            printf("%d\n",num[temp]-dis[a]-1);
        }
    }
    return 0;
}