洛谷P1196 [NOI2002]银河英雄传说 并查集

#include<cstdio>
#include<cstring>

using namespace std;

int find(int);
int abs(int);
void setup();

int fa[30005];
int size[30005];
int d[30005];
int T,x,y,fx,fy;
char f;

int main(){
    setup();
    scanf("%d",&T);
    for(int i=1;i<=T;i++){
        do{
            f=getchar();
        }while(f!='M' && f!='C');
        scanf("%d%d",&x,&y);
        fx=find(x);
        fy=find(y);
        if(f=='C'){
            if(fx==fy)printf("%d
",abs(d[x]-d[y])-1);
            else printf("-1
");
        }
        else{
            fa[fx]=fy;
            d[fx]=size[fy];
            size[fy]+=size[fx];
        }
    }
    
    return 0;
}

int find(int x){  //无需处理size 
    if(fa[x]==x)return x;
    else{
        int gf=find(fa[x]);
        d[x]+=d[fa[x]];
        return fa[x]=gf;
    }
}

int abs(int x){
    if(x<0)return -x;
    else return x;
}

void setup(){
    for(int i=1;i<=30000;i++){
        fa[i]=i;
        size[i]=1;
        d[i]=0;
    }
}