acdream 1032 树形dp

 1 #include <iostream>
 2 #include <cstring>
 3 #include <cstdio>
 4 using namespace std;
 5 
 6 const int INF = 999999999;
 7 const int N = 2001;
 8 int value[N];
 9 int head[N];
10 int dp[N][N];
11 int cnt[N];
12 int ans[N];
13 int n, e;
14 
15 struct Edge 
16 {
17     int v, next;
18 } edge[N * 2];
19 
20 void addEdge( int u, int v )
21 {
22     edge[e].v = v;
23     edge[e].next = head[u];
24     head[u] = e++;
25 }
26 
27 void dfs( int u, int fa )
28 {
29     dp[u][1] = value[u];
30     cnt[u] = 1;
31     for ( int i = head[u]; i != -1; i = edge[i].next )
32     {
33         int v = edge[i].v;
34         if ( v == fa ) continue;
35         dfs( v, u );
36         cnt[u] += cnt[v];
37     }
38     for ( int i = head[u]; i != -1; i = edge[i].next )
39     {
40         int v = edge[i].v;
41         if ( v == fa ) continue;
42         for ( int j = cnt[u]; j > 1; j-- )
43         {
44             for ( int k = 1; k <= cnt[v] && k < j; k++ )
45             {
46                 dp[u][j] = min( dp[u][j], dp[u][j - k] + dp[v][k] );
47             }
48         }
49     }
50 }
51 
52 int main ()
53 {
54     while ( scanf("%d", &n) != EOF )
55     {
56         e = 0;
57         memset( head, -1, sizeof(head) );
58         for ( int i = 1; i <= n; i++ )
59         {
60             scanf("%d", value + i);
61         }
62         for ( int i = 1; i < n; i++ )
63         {
64             int u, v;
65             scanf("%d%d", &u, &v);
66             addEdge( u, v );
67             addEdge( v, u );
68         }
69         for ( int i = 1; i <= n; i++ )
70         {
71             for ( int j = 1; j <= n; j++ )
72             {
73                 dp[i][j] = INF;
74             }
75         }
76         dfs( 1, -1 );
77         for ( int i = 1; i <= n; i++ )
78         {
79             ans[i] = INF;
80             for ( int j = 1; j <= n; j++ )
81             {
82                 ans[i] = min( ans[i], dp[j][i] );
83             }
84             printf("%d", ans[i]);
85             if ( i != n ) putchar(‘ ‘);
86             else putchar(‘\n‘);     
87         }
88     }
89     return 0;
90 }