codeforces#P1795F. Blocking Chips
Blocking Chips
本题没有可用的提交语言。
Description
You are given a tree, consisting of $n$ vertices. There are $k$ chips, placed in vertices $a_1, a_2, \dots, a_k$. All $a_i$ are distinct. Vertices $a_1, a_2, \dots, a_k$ are colored black initially. The remaining vertices are white.
You are going to play a game where you perform some moves (possibly, zero). On the $i$-th move ($1$-indexed) you are going to move the $((i - 1) \bmod k + 1)$-st chip from its current vertex to an adjacent white vertex and color that vertex black. So, if $k=3$, you move chip $1$ on move $1$, chip $2$ on move $2$, chip $3$ on move $3$, chip $1$ on move $4$, chip $2$ on move $5$ and so on. If there is no adjacent white vertex, then the game ends.
What's the maximum number of moves you can perform?
The first line contains a single integer $t$ ($1 \le t \le 10^4$) — the number of testcases.
The first line of each testcase contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$) — the number of vertices of the tree.
Each of the next $n - 1$ lines contains two integers $v$ and $u$ ($1 \le v, u \le n$) — the descriptions of the edges. The given edges form a tree.
The next line contains a single integer $k$ ($1 \le k \le n$) — the number of chips.
The next line contains $k$ integers $a_1, a_2, \dots, a_k$ ($1 \le a_i \le n$) — the vertices with the chips. All $a_i$ are distinct.
The sum of $n$ over all testcases doesn't exceed $2 \cdot 10^5$.
For each testcase, print a single integer — the maximum number of moves you can perform.
Input
The first line contains a single integer $t$ ($1 \le t \le 10^4$) — the number of testcases.
The first line of each testcase contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$) — the number of vertices of the tree.
Each of the next $n - 1$ lines contains two integers $v$ and $u$ ($1 \le v, u \le n$) — the descriptions of the edges. The given edges form a tree.
The next line contains a single integer $k$ ($1 \le k \le n$) — the number of chips.
The next line contains $k$ integers $a_1, a_2, \dots, a_k$ ($1 \le a_i \le n$) — the vertices with the chips. All $a_i$ are distinct.
The sum of $n$ over all testcases doesn't exceed $2 \cdot 10^5$.
Output
For each testcase, print a single integer — the maximum number of moves you can perform.
5
5
1 2
2 3
3 4
4 5
1
3
5
1 2
2 3
3 4
4 5
2
1 2
5
1 2
2 3
3 4
4 5
2
2 1
6
1 2
1 3
2 4
2 5
3 6
3
1 4 6
1
1
1
2
0
1
2
0