POJ1988 Cube Stacking (！hard）

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.

题目大意：（同银河舰队传说） 对于n块积木，进行两种操作：M a b 把a移到b上，C a 询问a下面有几块积木。

思路：用并查集和tot，sum数组维护，像银河一样简单AC。。。

code：

#include<iostream>

#include<cstdio>

using namespace std;

int fa[30001]={0},sum[30001]={0},len[30001]={0};

int rool(int x)

{

int j;

if (fa[x]!=x)

{

j=rool(fa[x]);

len[x]=len[x]+len[fa[x]];

fa[x]=j;

}

return fa[x];

}

int main()

{

int p,n,i,j,r1,r2,x,y;

char ch;

scanf("%d",&p);

n=30000;

for (i=1;i<=n;++i)

{

fa[i]=i;

sum[i]=1;

}

for (i=1;i<=p;++i)

{

scanf("%*c%c",&ch);

if (ch==‘M‘)

{

scanf("%d%d",&x,&y);

r1=rool(x);

r2=rool(y);

if (r1!=r2)

{

len[r1]=len[r1]+sum[r2];

sum[r2]=sum[r2]+sum[r1];

fa[r1]=r2;

}

}

else

{

scanf("%d",&x);

r1=rool(x);

printf("%d\n",len[x]);

}

}

}