并查集

 1 #include<cstdio>
 2 #include<cstring>
 3 #define mt(a,b) memset(a,b,sizeof(a))
 4 const int M=30010;
 5 class UnionFindSet {  //并查集
 6     int par[M],num[M];
 7 public:
 8     int getnum(int id){
 9         return num[getroot(id)];
10     }
11     void init() {
12         mt(par,-1);
13         for(int i=0;i<M;i++) num[i]=1;
14     }
15     int getroot(int x) {
16         int i=x,j=x,temp;
17         while(par[i]>=0) i=par[i];
18         while(j!=i) {
19             temp=par[j];
20             par[j]=i;
21             j=temp;
22         }
23         return i;
24     }
25     bool unite(int x,int y) {
26         int p=getroot(x);
27         int q=getroot(y);
28         if(p==q)return false;
29         if(par[p]>par[q]) {
30             par[q]+=par[p];
31             par[p]=q;
32             num[q]+=num[p];
33         } else {
34             par[p]+=par[q];
35             par[q]=p;
36             num[p]+=num[q];
37         }
38         return true;
39     }
40 }gx;
41 int main(){
42     int n,m,op,x,y;
43     while(~scanf("%d%d",&n,&m),n|m){
44         gx.init();
45         while(m--){
46             scanf("%d",&op);
47             if(!op) continue;
48             scanf("%d",&x);
49             op--;
50             while(op--){
51                 scanf("%d",&y);
52                 gx.unite(x,y);
53             }
54         }
55         printf("%d\n",gx.getnum(0));
56     }
57     return 0;
58 }