2018_2_10_Cube Stacking_并查集进阶

#include<iostream>
#include<cstdio>
#include<algorithm>
#include<string>
#include<cstring>
#include<vector>
#include<map>
#include<list> 

const int maxn=1e5+5;
using namespace std;
int set[maxn],cnt[maxn],top[maxn];

int set_find(int p){
	if(set[p]<0)
	return p;
	if(set[set[p]]>=0){
		int fa=set[p];
		set[p]=set_find(fa);
		cnt[p]+=cnt[fa];
	}
	return set[p];
}

void set_join(int x,int y){
	x=set_find(x);
	y=set_find(y);
	set[x]=y;
	set_find(top[y]);
	cnt[x]=cnt[top[y]]+1;
	top[y]=top[x];
}

int main(){
	int p;
	scanf("%d",&p);
	memset(set,-1,sizeof(set));
	memset(cnt,0,sizeof(cnt));
	for(int i=0;i<maxn;i++)
	top[i]=i;
	while(p--){
		char s[5];
		scanf("%s",s);
		if(s[0]=='M'){
			int x,y;
			scanf("%d%d",&x,&y);
			set_join(x,y);
		}else{
			int x;
			scanf("%d",&x);
			set_find(x);
			printf("%d\n",cnt[x]);
		}
	}
	return 0;
}

Time Limit: 2000MS		Memory Limit: 30000K
Total Submissions: 26562		Accepted: 9305
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