poj 1611 The Suspects

并查集简单题
 1 #include<cstdio>
 2 #include<memory.h>
 3 int par[1000];
 4 int Find(int x)
 5 {
 6     while(par[x] >= 0)
 7         x = par[x];
 8     return x;
 9 }
10 void Merge(int x,int y)
11 {
12     int a,b;
13     int tmp;
14     a = Find(x);
15     b = Find(y);
16     if(a != b)
17     {
18         tmp = par[a] + par[b];
19         if(a < b) //0 shi gan ran suoyi xiaode youxian
20         {
21             par[b] = a;
22             par[a] = tmp;
23         }
24         else
25         {
26             par[a] = b;
27             par[b] = tmp;
28         }
29     }
30 }
31 int main()
32 {
33     freopen("input.txt","r",stdin);
34     int a,b,n,m,t;
35     int cnt;
36     while(scanf("%d%d",&n,&m) && n)//这里不能scanf("%d%d",&n,&m) && n && m) 因为m为0时同样可以
37     {
38 
39         memset(par,-1,sizeof(par));
40         while(m--)
41         {
42             scanf("%d",&t);
43             scanf("%d",&a);
44             t--;
45             while(t--)
46             {
47                 scanf("%d",&b);
48                 Merge(a,b);
49             }
50         }
51 
52         printf("%d
",-par[0]);
53     }
54 }