Binary Apple Tree

Let’s imagine how apple tree looks in binary computer world. You’re right, it looks just like a binary tree, i.e. any biparous branch splits up to exactly two new branches. We will enumerate by integers the root of binary apple tree, points of branching and the ends of twigs. This way we may distinguish different branches by their ending points. We will assume that root of tree always is numbered by 1 and all numbers used for enumerating are numbered in range from 1 to N, where N is the total number of all enumerated points. For instance in the picture below N is equal to 5. Here is an example of an enumerated tree with four branches:
2 5
\ /
3 4
\ /
1
As you may know it’s not convenient to pick an apples from a tree when there are too much of branches. That’s why some of them should be removed from a tree. But you are interested in removing branches in the way of minimal loss of apples. So your are given amounts of apples on a branches and amount of branches that should be preserved. Your task is to determine how many apples can remain on a tree after removing of excessive branches.
Input
First line of input contains two numbers: N and Q ( 2 ≤ N ≤ 100; 1 ≤ Q ≤ N − 1 ). N denotes the number of enumerated points in a tree. Q denotes amount of branches that should be preserved. Next N − 1 lines contains descriptions of branches. Each description consists of a three integer numbers divided by spaces. The first two of them define branch by it’s ending points. The third number defines the number of apples on this branch. You may assume that no branch contains more than 30000 apples.
Output
Output should contain the only number — amount of apples that can be preserved. And don’t forget to preserve tree’s root
Example
input
5 2
1 3 1
1 4 10
2 3 20
3 5 20
output
21

令人措手不及的学习曲线。。。

一道树形dp中典型的二叉苹果树的问题
AcWing：https://www.acwing.com/problem/content/1076/
膜拜大佬

f[i][j]表示：第i个子树保留j个节点时的最大权值

#include
#include
#include
using namespace std;
const int N=110,M=N*2;
int n,m;
int h[N],e[M],ne[M],w[M],idx;
int f[N][N];
void add(int a,int b,int c)//建表
{
e[idx]=b;
w[idx]=c;
ne[idx]=h[a];
h[a]=idx++;
}
void dfs(int u,int father)
{
for(int i=h[u];i!=-1;i=ne[i])//物品组
{
    if(e[i]==father)
    continue;
    dfs(e[i],u);
    //分组背包问题
    for(int j=m;j>=0;j--)//枚举体积
    {
        for(int k=0;k>n>>m;
memset(h,-1,sizeof h);
for(int i=0;i>a>>b>>c;//建立无向图
    add(a,b,c);
    add(b,a,c);
}
dfs(1,-1);//因为为无向图，所以需要记录父节点
cout<