洛谷 1196 银河英雄传说

//Twenty
#include<algorithm>
#include<iostream>
#include<cstdlib>
#include<cstring>
#include<cstdio>
#include<cmath>
#include<ctime>
#include<queue>
const int maxn=30005;
using namespace std;
typedef long long LL;
int n,fa[maxn],d[maxn],sz[maxn],x,y,u,v,top;
char op[5];

void read(int &ret) {
    int f=1; ret=0; char ch=getchar();
    while(ch!=‘-‘&&(ch<‘0‘||ch>‘9‘)) ch=getchar();
    if(ch==‘-‘) f=-1,ch=getchar();
    for(;ch>=‘0‘&&ch<=‘9‘;ch=getchar()) ret=ret*10+ch-‘0‘; ret*=f;
}

int find(int x) {
    if(x==fa[x]) {return top=x;}
    else {
	    find(fa[x]);
	    d[x]+=d[fa[x]];
	    fa[x]=top;
	    return top;
	}
}

void init() {
	read(n);
	for(int i=1;i<maxn;i++) fa[i]=i,sz[i]=1,d[i]=0;
	for(int i=1;i<=n;i++) {
	    scanf("%s",op);
	    read(x); read(y);
	    top=0;
	    u=find(x); 
	    top=0;
		v=find(y);
	    if(op[0]==‘C‘) {
	    	if(u!=v) printf("-1\n");
	    	else {
			    printf("%d\n",abs(d[x]-d[y])-1);
 			}
		}
		else {
		    if(u==v) continue;
			d[u]=sz[v];
			sz[v]+=sz[u];
		    fa[u]=v;
		}
	}
}

int main()
{
	init();
	return 0;
}