POJ——T 1988 Cube Stacking || HDU ——T 2818 Building Block

 1 #include <algorithm>
 2 #include <cstdio>
 3 
 4 using namespace std;
 5 
 6 const int N(30005);
 7 int fa[N],sum[N],beh[N];
 8 
 9 int find(int x)
10 {
11     if(fa[x]==x) return x;
12     int dad=find(fa[x]);
13     beh[x]+=beh[fa[x]];
14     return fa[x]=dad;
15 }
16 inline void combine(int x,int y)
17 {
18     x=find(x),y=find(y);
19     if(x==y) return ;
20     beh[x]+=sum[y];
21     sum[y]+=sum[x];
22     fa[x]=y;
23 }
24 
25 int main()
26 {
27     for(int i=1;i<N;i++)
28         fa[i]=i,sum[i]=1;
29     int p,u,v; scanf("%d",&p);
30     for(char ch;p--;)
31     {
32         scanf("\n%c%d",&ch,&u);
33         if(ch==‘M‘)
34         {
35             scanf("%d",&v);
36             combine(u,v);
37         }
38         else find(u),printf("%d\n",beh[u]);
39     }
40     return 0;
41 }