bzoj 1086 树分块

 

将树分成一些块,做法见vfleaking博客。

 

 1 /**************************************************************
 2     Problem: 1086
 3     User: idy002
 4     Language: C++
 5     Result: Accepted
 6     Time:20 ms
 7     Memory:852 kb
 8 ****************************************************************/
 9  
10 #include <cstdio>
11 #include <vector>
12 #define maxn 1010
13 using namespace std;
14  
15  
16 int n, b;
17 int mccno[maxn];
18 int cent[maxn], mtot;
19 vector<int> mcc[maxn];
20 vector<int> g[maxn], remain[maxn];
21  
22 void dfs( int u, int fa ) {
23     for( int t=0; t<g[u].size(); t++ ) {
24         int v = g[u][t];
25         if( v==fa ) continue;
26         dfs(v,u);
27         while( remain[v].size() ) {
28             remain[u].push_back( remain[v].back() );
29             remain[v].pop_back();
30         }
31         if( remain[u].size() >= b ) {
32             mtot++;
33             cent[mtot] = u;
34             while( !remain[u].empty() ) {
35                 mccno[ remain[u].back() ] = mtot;
36                 mcc[ mtot ].push_back( remain[u].back() );
37                 remain[u].pop_back();
38             }
39         }
40     }
41     remain[u].push_back( u );
42 }
43  
44 int main() {
45     scanf( "%d%d", &n, &b );
46     for( int i=1,u,v; i<n; i++ ) {
47         scanf( "%d%d", &u, &v );
48         g[u].push_back(v);
49         g[v].push_back(u);
50     }
51     dfs(1,0);
52     while( !remain[1].empty() ) {
53         mccno[ remain[1].back() ] = mtot;
54         mcc[ mtot ].push_back( remain[1].back() );
55         remain[1].pop_back();
56     }
57     printf( "%d\n", mtot );
58     for( int i=1; i<=n; i++ )
59         printf( "%d ", mccno[i] );
60     printf( "\n" );
61     for( int i=1; i<=mtot; i++ )
62         printf( "%d ", cent[i] );
63     printf( "\n" );
64 }
View Code

 

posted @ 2015-02-22 17:20  idy002  阅读(...)  评论(... 编辑 收藏