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Time Limit: 5 s Memory Limit: 1024 MB Total points: 100

#6738. 覆盖

Statistics

给定一棵有 $n$ 个顶点和 $n-1$ 条边的树。每个顶点的度数最多为 $k$。

现有 $m$ 条无向简单路径;第 $i$ 条路径的起点为 $a_i$,终点为 $b_i$,权重为 $w_i$。当且仅当删除边 $e$ 后顶点 $x$ 和 $y$ 不连通时,我们称边 $e$ 被路径 $(x, y)$ 覆盖。

请找出一个路径子集 $S$,使得每条边被 $S$ 中的路径覆盖次数不超过一次。你的目标是最大化 $\sum_{i \in S} w_i$。

输入格式

第一行包含三个整数 $n, m, k$ ($2 \le n \le 10^5, 0 \le m \le 5 \times 10^5, 1 \le k \le 12$)。

接下来的 $n-1$ 行,每行包含两个整数 $x, y$ ($1 \le x, y \le n$),表示给定树中连接顶点 $x$ 和 $y$ 的一条边。

接下来的 $m$ 行中,第 $i$ 行包含三个整数 $a_i, b_i, w_i$ ($1 \le a_i, b_i \le n, 0 \le w_i \le 10^9, a_i \neq b_i$)。

输出格式

输出一行,包含一个整数,表示答案。

样例

样例输入 1

5 7 3
1 2
1 3
2 4
2 5
3 2 8
5 4 10
3 1 2
1 2 7
2 1 2
1 2 1
5 2 3

样例输出 1

19

Editorials

IDTypeStatusTitlePosted ByLast UpdatedActions
#156EditorialOpen题解jiangly2025-12-12 23:38:47View

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