带权并查集

#include<iostream>
#include<algorithm>
#include<cstdio>

using namespace std;

int n,m,w;
int vis[3000000];
int dis[3000000];
int fa[3000000];

void init()
{
    int i,j,k;
    for(int i=1; i<=n; i++)
    {
        vis[i]=1;
        dis[i]=0;
    }
}
int findfather(int x)
{
    int a;
    if(x==fa[x])
        return x;
    else
    {
        a=fa[x];
        fa[x]=findfather(a);
        dis[x]+=dis[a];
    }
    return fa[x];
}
void join(int nowx,int nowy)
{
    int newx=findfather(nowx);
    int newy=findfather(nowy);
    if(newx!=newy)
    {
        fa[newx]=newy;
        dis[newx]=vis[newy];
        vis[newy]+=vis[newx];
    }
}
int main()
{
    cin >> n;
    for(int i=1; i<=n; i++)
        fa[i]=i;
    init();
    int o=n;
    char ch;
    int A,B,e;
    while(n--)
    {
        cin >> ch;
        if(ch=='M')
        {
            scanf("%d%d",&A,&B);
            if(findfather(A)!=findfather(B))
            {
                join(A,B);
            }
        }
        else if(ch=='C')
        {
            scanf("%d",&e);
            findfather(e);
            printf("%d\n",dis[e]);
        }
    }

}