luogu_1196 银河英雄传说

#include <cstdio>
#include <iostream>
#include <cctype>
#include <cmath>
#include <algorithm>
using namespace std;
const int N=30010;
int p[N],t,s[N],d[N],num[N],x,y;
char c;

int find(int x){
    if(x==p[x])return x;
    int fx=find(p[x]);
    d[x]+=d[p[x]];
    return p[x]=fx;
}

int main(){
    for(int i=1;i<=30000;i++){p[i]=i; d[i]=0; num[i]=1;}
    scanf("%d",&t);
    while(t--){
        cin>>c>>x>>y;
        int fx=find(x),fy=find(y);
        if(c=='M'){
            d[fx]+=num[fy];
            p[fx]=fy;
            num[fy]+=num[fx];
            num[fx]=0;
        }
        else{
            if(fx!=fy){printf("-1\n"); continue;}
            printf("%d\n",abs(d[x]-d[y])-1);
        }
    }
    return 0;
}