poj 2236 并查集

并查集水题

 #include<cstdio>
 #include<iostream>
 #include<algorithm>
 #include<cstring>
 #include<cmath>
 #include<queue>
 using namespace std;
 int n,m,t;
 struct node
 {
     int x,y;
 }A[];
 int rank[],pre[];
 int dist(node A,node B)
 {
     return (A.x-B.x)*(A.x-B.x)+(A.y-B.y)*(A.y-B.y);
 }
 void init(int n)
 {
     for(int i=;i<=n;i++)
     {
         rank[i]=;
         pre[i]=i;
     }
 }
 int find(int x)
 {
     if(pre[x]!=x)    pre[x]=find(pre[x]);
     return pre[x];
 }
 void Union(int x,int y)
 {
     x=find(x);
     y=find(y);
     if(x==y)    return;
     if(rank[x]>=rank[y])
     {
         pre[y]=x;
         rank[x]+=rank[y];
     }
     else
     {
         pre[x]=y;
         rank[y]+=rank[x];
     }
 }
 int main()
 {
     int i,j,k;
     //freopen("1.in","r",stdin);
     scanf("%d",&n);
     init(n);
     scanf("%d",&k);
     for(i=;i<=n;i++)   scanf("%d%d",&A[i].x,&A[i].y);
     char s[];
     int aa[],tot=;
     while(scanf("%s",s)!=EOF)
     {
         if(s[]=='O')
         {
             int q;
             scanf("%d",&q);
             for(i=;i<tot;i++)
             {
                 if(dist(A[aa[i]],A[q])<=k*k)
                 {
                    // printf("%d %d\n",aa[i],q);
                     Union(aa[i],q);
                 }
             }
             aa[tot++]=q;
         }
         else
         {
             int p,q;
             scanf("%d%d",&p,&q);
             p=find(p);
             q=find(q);
             if(p==q)    printf("SUCCESS\n");
             else printf("FAIL\n");
         }
     }
     return ;
 }