Codeforces Round 975 (Div. 2)
E
Tree Pruning
Codeforces
未评级
原题
← DF →
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You are given a tree with $n$ nodes, rooted at node $1$. In this problem, a leaf is a non-root node with degree $1$.

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In one operation, you can remove a leaf and the edge adjacent to it (possibly, new leaves appear). What is the minimum number of operations that you have to perform to get a tree, also rooted at node $1$, where all the leaves are at the same distance from the root?

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Input

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Each test contains multiple test cases. The first line contains the number of test cases $t$ ($1 \le t \le 10^4$). The description of the test cases follows.

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The first line of each test case contains a single integer $n$ ($3 \leq n \leq 5 \cdot 10^5$) — the number of nodes.

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Each of the next $n-1$ lines contains two integers $u$, $v$ ($1 \leq u, v \leq n$, $u \neq v$), describing an edge that connects $u$ and $v$. It is guaranteed that the given edges form a tree.

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It is guaranteed that the sum of $n$ over all test cases does not exceed $5 \cdot 10^5$.

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Output

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For each test case, output a single integer: the minimum number of operations needed to achieve your goal.

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Note

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In the first two examples, the tree is as follows:

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image

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In the first example, by removing edges $(1, 3)$ and $(2, 5)$, the resulting tree has all leaves (nodes $6$ and $7$) at the same distance from the root (node $1$), which is $3$. The answer is $2$, as it is the minimum number of edges that need to be removed to achieve the goal.

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In the second example, removing edges $(1, 4)$ and $(5, 7)$ results in a tree where all leaves (nodes $4$ and $5$) are at the same distance from the root (node $1$), which is $2$.

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样例

Input #1
3
7
1 2
1 3
2 4
2 5
4 6
4 7
7
1 2
1 3
1 4
2 5
3 6
5 7
15
12 9
1 6
6 14
9 11
8 7
3 5
13 5
6 10
13 15
13 6
14 12
7 2
8 1
1 4
Output #1
2
2
5
InputCopy OutputCopy
题目信息
题号
2019E
时间限制
3 s
内存限制
256 MB

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。