Python 代码

N = 210
n, k = map(int, input().split())
h, e, ne, w = [-1] * N, [0] * N, [0] * N, [0] * N
idx = 0

def add(a, b, c):
    global idx
    e[idx], w[idx] = b, c
    h[a], ne[idx] = idx, h[a]
    idx += 1

def dfs(cur, pre, dep, num):
    global k
    dp = [0] * (k + 1)
    if dep > k: return dp
    for i in range(1, k+1): dp[i] = num

    nn = h[cur]
    while nn != -1:
        son, wei = e[nn], w[nn]
        if son != pre:
            dp_son = dfs(son, cur, dep + 1, wei)
            for i in range(k, -1, -1):
                for j in range(k+1):
                    if (cur == 1 and i - j >= 0) or (cur != 1 and i - j >= 1):
                        dp[i] = max(dp[i], dp[i-j] + dp_son[j])
        nn = ne[nn]
    return dp
for _ in range(n - 1):
    a, b, c = map(int, input().split())
    add(a, b, c)
    add(b, a, c)

dp = dfs(1, -1, 0, 0)
print(dp[k])