POJ2236 Wireless Network 并查集

#include<cstdio>
#include<cstring>
#include<queue>
#include<set>
#include<cstdlib>
#include<algorithm>
#include<vector>
#include<cmath>
using namespace std;
typedef long long LL;
typedef pair<int,int>pii;
const int N=1e3+5;
const int INF=0x3f3f3f3f;
pii o[N];
bool vis[N];
int fa[N];
int find(int x){
   return fa[x]==x?x:fa[x]=find(fa[x]);
}
int dis(int i,int j){
   return (o[i].first-o[j].first)*(o[i].first-o[j].first)+(o[i].second-o[j].second)*(o[i].second-o[j].second);
}
int main(){
    int n,d,x,y;
    scanf("%d%d",&n,&d);
    for(int i=1;i<=n;++i)
        scanf("%d%d",&o[i].first,&o[i].second),fa[i]=i;
    char s[10];
    while(~scanf("%s",s)){
        if(s[0]==‘O‘){
          scanf("%d",&x);
          if(vis[x])continue;
          for(int i=1;i<=n;++i){
            if(!vis[i]||dis(x,i)>d*d)continue;
            int u=find(x),v=find(i);
            if(u!=v)fa[u]=v;
          }
          vis[x]=true;
        }
        else {
          scanf("%d%d",&x,&y);
          x=find(x),y=find(y);
          if(x==y)printf("SUCCESS\n");
          else printf("FAIL\n");
        }
    }
    return 0;
}