poj 1988 （并查集）

#include<iostream>
#include<cstdio>
#include<cstring>
#include<cmath>
#include<cstdlib>
using namespace std;
#define MAXN 30010
int father[MAXN],rank[MAXN];
int num[MAXN]; //根节点x记录集合的数量
void make_set(int x)
{
    father[x]=x;
    num[x]=1;//初始化每个根节点x的数量为1
}
int find_set(int x)
{
    if(x==father[x]) return x;
    else 
    {
        int t=father[x];
        father[x]=find_set(father[x]);
        rank[x]=rank[x]+rank[t]; //压缩路径
        return father[x];
    }
}
void union_set(int x,int y)
{
    int rx=find_set(x);
    int ry=find_set(y);
    father[rx]=ry;
    rank[rx]=num[ry];
    num[ry]+=num[rx];
    
}
int main()
{
    int i,n,x,y;
    char c[10];
    scanf("%d",&n);
    for(i=1;i<=30000;i++)
        make_set(i);
    while(n--)
    {
        scanf("%s",c);
        if(c[0]=='M')
        {
            scanf("%d%d",&x,&y);
            int rx=find_set(x);
            int ry=find_set(y);
            if(rx!=ry)
                union_set(x,y);
        }
        else
        {
            scanf("%d",&x);
            find_set(x);
            printf("%d\n",rank[x]);
        }

    }
    return 0;
}