Polynomial Round 2022 (Div. 1 + Div. 2, Rated, Prizes!)
E
Two Chess Pieces
Codeforces
1900
原题
← DF1 →
翻译中…

Cirno_9baka has a tree with $n$ nodes. He is willing to share it with you, which means you can operate on it.

翻译中…

Initially, there are two chess pieces on the node $1$ of the tree. In one step, you can choose any piece, and move it to the neighboring node. You are also given an integer $d$. You need to ensure that the distance between the two pieces doesn't ever exceed $d$.

翻译中…

Each of these two pieces has a sequence of nodes which they need to pass in any order, and eventually, they have to return to the root. As a curious boy, he wants to know the minimum steps you need to take.

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Input

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The first line contains two integers $n$ and $d$ ($2 \le d \le n \le 2\cdot 10^5$).

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The $i$-th of the following $n - 1$ lines contains two integers $u_i, v_i$ $(1 \le u_i, v_i \le n)$, denoting the edge between the nodes $u_i, v_i$ of the tree.

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It's guaranteed that these edges form a tree.

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The next line contains an integer $m_1$ ($1 \le m_1 \le n$) and $m_1$ integers $a_1, a_2, \ldots, a_{m_1}$ ($1 \le a_i \le n$, all $a_i$ are distinct)  — the sequence of nodes that the first piece needs to pass.

翻译中…

The second line contains an integer $m_2$ ($1 \le m_2 \le n$) and $m_2$ integers $b_1, b_2, \ldots, b_{m_2}$ ($1 \le b_i \le n$, all $b_i$ are distinct)  — the sequence of nodes that the second piece needs to pass.

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Output

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Output a single integer  — the minimum steps you need to take.

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Note

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In the first sample, here is one possible sequence of steps of length $6$.

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  • The second piece moves by the route $1 \to 2 \to 4 \to 2 \to 1$.
  • Then, the first piece moves by the route $1 \to 3 \to 1$.
翻译中…

In the second sample, here is one possible sequence of steps of length $8$:

翻译中…
  • The first piece moves by the route $1 \to 2 \to 3$.
  • Then, the second piece moves by the route $1 \to 2$.
  • Then, the first piece moves by the route $3 \to 4 \to 3 \to 2 \to 1$.
  • Then, the second piece moves by the route $2 \to 1$.
翻译中…

样例

Input #1
4 2
1 2
1 3
2 4
1 3
1 4
Output #1
6
InputCopy OutputCopy
Input #2
4 2
1 2
2 3
3 4
4 1 2 3 4
1 1
Output #2
8
InputCopy OutputCopy
题目信息
题号
1774E
时间限制
2 s
内存限制
256 MB
标签
DFS 及类似
动态规划
贪心
树

题面与样例版权归 Codeforces 及出题人所有;中文翻译由 AI 生成(CI 管线),如有出入请以原文为准。