P2015

 1 #include<iostream>
 2 #include<cstdio>
 3 #include<algorithm>
 4 #include<cstring>
 5 using namespace std;
 6 const int maxn=200;
 7 struct edge{
 8     int to,nxt,dis;
 9 }e[maxn];
10 int n,m;
11 inline int read()
12 {
13     int x;char c=getchar();
14     while(c<'0' or c>'9')c=getchar();
15     x=c-'0',c=getchar();
16     while(c>='0' and c<='9')x=x*10+c-'0',c=getchar();
17     return x;
18 }
19 int head[maxn],ecnt,f[maxn][maxn];
20 inline void addedge(int from,int to,int dis)
21 {
22     e[++ecnt]=(edge){to,head[from],dis},head[from]=ecnt;
23 }
24 int siz[maxn];
25 void dfs(int x,int fa)
26 {
27     for(int i=head[x];i;i=e[i].nxt)
28     {
29         int u=e[i].to;
30         if(u==fa)continue;
31         dfs(u,x);
32         siz[x]+=siz[u]+1;
33         for(int j=min(siz[x],m);j;j--)
34             for(int k=min(siz[u],j-1);k>=0;k--)
35             f[x][j]=max(f[x][j],f[x][j-k-1]+f[u][k]+e[i].dis);
36             //j表示保留j时，k全部遍历所有情况 
37     }
38 }
39 
40 int main()
41 {
42     n=read(),m=read();
43     for(int a,b,c,i=1;i<n;i++)
44     {
45         a=read(),b=read(),c=read();
46         addedge(a,b,c);addedge(b,a,c);
47     }
48     dfs(1,0);
49     printf("%d",f[1][m]);
50     return 0;
51 }