bzoj 1086 树分块

将树分成一些块，做法见vfleaking博客。

 /**************************************************************
     Problem: 1086
     User: idy002
     Language: C++
     Result: Accepted
     Time:20 ms
     Memory:852 kb
 ****************************************************************/

 #include <cstdio>
 #include <vector>
 #define maxn 1010
 using namespace std;

 int n, b;
 int mccno[maxn];
 int cent[maxn], mtot;
 vector<int> mcc[maxn];
 vector<int> g[maxn], remain[maxn];

 void dfs( int u, int fa ) {
     for( int t=; t<g[u].size(); t++ ) {
         int v = g[u][t];
         if( v==fa ) continue;
         dfs(v,u);
         while( remain[v].size() ) {
             remain[u].push_back( remain[v].back() );
             remain[v].pop_back();
         }
         if( remain[u].size() >= b ) {
             mtot++;
             cent[mtot] = u;
             while( !remain[u].empty() ) {
                 mccno[ remain[u].back() ] = mtot;
                 mcc[ mtot ].push_back( remain[u].back() );
                 remain[u].pop_back();
             }
         }
     }
     remain[u].push_back( u );
 }

 int main() {
     scanf( "%d%d", &n, &b );
     for( int i=,u,v; i<n; i++ ) {
         scanf( "%d%d", &u, &v );
         g[u].push_back(v);
         g[v].push_back(u);
     }
     dfs(,);
     while( !remain[].empty() ) {
         mccno[ remain[].back() ] = mtot;
         mcc[ mtot ].push_back( remain[].back() );
         remain[].pop_back();
     }
     printf( "%d\n", mtot );
     for( int i=; i<=n; i++ )
         printf( "%d ", mccno[i] );
     printf( "\n" );
     for( int i=; i<=mtot; i++ )
         printf( "%d ", cent[i] );
     printf( "\n" );
 }