记录一下错误点

#include <cmath>
#include <cstdio>
#include <vector>
#include <iostream>
#include <algorithm>
using namespace std;
int fa[102000];
int sz[102000];
int find(int x){
    return x==fa[x]?x:fa[x]=find(fa[x]);
}
void merge(int x,int y){
    int py=find(y),px=find(x);
    if(px == py) return;//if belongs to the same community don't merge
    sz[py]+=sz[px]; 
    fa[px]=py;
}
int main() {
    for(int i=1;i<101000;i++) fa[i]=i,sz[i]=1;
    int n,q;cin>>n>>q;
    for(int i=0;i<q;i++){
        char c;cin>>c;
        if(c=='M'){
            int m,n;cin>>m>>n;
            merge(m,n);
        }else{
            int m;cin>>m;
            m=find(m);
            cout<<sz[m]<<endl;
        }
    }
    return 0;
}