hdu--4496--并查集

 1 #include <iostream>
 2 #include <cstring>
 3 using namespace std;
 4 
 5 int n;
 6 const int size = 10100;
 7 int father[size] , ans[size*10] , from[size*10] , to[size*10];
 8 
 9 int find( int x )
10 {
11     return father[x] == -1 ? x : father[x] = find( father[x] );
12 }
13 
14 int main()
15 {
16     int m , sum , x , y;
17     while( ~scanf("%d%d",&n,&m) )
18     {
19         sum = n;
20         memset( father , -1 , sizeof(father) );
21         for( int i = 0 ; i<m ; i++ )
22         {
23             scanf("%d%d",&from[i],&to[i]);
24         }
25         for( int i =  m-1 ; i>=0 ; i-- )
26         {
27             ans[i] = sum;
28             x = find( from[i] );
29             y = find( to[i] );
30             if( x!=y )
31             {
32                 -- sum;
33                 father[x] = y;
34             }    
35         }
36         for( int i = 0 ; i<m ; i++ )
37         {
38             printf("%d\n",ans[i]);
39         }
40     }
41     return 0;
42 }