poj 2236 并查集

并查集水题
 1 #include<cstdio>
 2 #include<iostream>
 3 #include<algorithm>
 4 #include<cstring>
 5 #include<cmath>
 6 #include<queue>
 7 using namespace std;
 8 int n,m,t;
 9 struct node
10 {
11     int x,y;
12 }A[1005];
13 int rank[1005],pre[1005];
14 int dist(node A,node B)
15 {
16     return (A.x-B.x)*(A.x-B.x)+(A.y-B.y)*(A.y-B.y);
17 }
18 void init(int n)
19 {
20     for(int i=1;i<=n;i++)
21     {
22         rank[i]=1;
23         pre[i]=i;
24     }
25 }
26 int find(int x)
27 {
28     if(pre[x]!=x)    pre[x]=find(pre[x]);
29     return pre[x];
30 }
31 void Union(int x,int y)
32 {
33     x=find(x);
34     y=find(y);
35     if(x==y)    return;
36     if(rank[x]>=rank[y])
37     {
38         pre[y]=x;
39         rank[x]+=rank[y];
40     }
41     else
42     {
43         pre[x]=y;
44         rank[y]+=rank[x];
45     }
46 }
47 int main()
48 {
49     int i,j,k;
50     //freopen("1.in","r",stdin);
51     scanf("%d",&n);
52     init(n);
53     scanf("%d",&k);
54     for(i=1;i<=n;i++)   scanf("%d%d",&A[i].x,&A[i].y);
55     char s[20];
56     int aa[1005],tot=0;
57     while(scanf("%s",s)!=EOF)
58     {
59         if(s[0]=='O')
60         {
61             int q;
62             scanf("%d",&q);
63             for(i=0;i<tot;i++)
64             {
65                 if(dist(A[aa[i]],A[q])<=k*k)
66                 {
67                    // printf("%d %d
",aa[i],q);
68                     Union(aa[i],q);
69                 }
70             }
71             aa[tot++]=q;
72         }
73         else
74         {
75             int p,q;
76             scanf("%d%d",&p,&q);
77             p=find(p);
78             q=find(q);
79             if(p==q)    printf("SUCCESS
");
80             else printf("FAIL
");
81         }
82     }
83     return 0;
84 }