310426: CF1831F. Mex Tree

Memory Limit:256 MB Time Limit:3 S
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Description

F. Mex Treetime limit per test3 secondsmemory limit per test256 megabytesinputstandard inputoutputstandard output

You are given a tree with $n$ nodes. For each node, you either color it in $0$ or $1$.

The value of a path $(u,v)$ is equal to the MEX$^\dagger$ of the colors of the nodes from the shortest path between $u$ and $v$.

The value of a coloring is equal to the sum of values of all paths $(u,v)$ such that $1 \leq u \leq v \leq n$.

What is the maximum possible value of any coloring of the tree?

$^{\dagger}$ The MEX (minimum excluded) of an array is the smallest non-negative integer that does not belong to the array. For instance:

  • The MEX of $[2,2,1]$ is $0$, because $0$ does not belong to the array.
  • The MEX of $[3,1,0,1]$ is $2$, because $0$ and $1$ belong to the array, but $2$ does not.
  • The MEX of $[0,3,1,2]$ is $4$ because $0$, $1$, $2$, and $3$ belong to the array, but $4$ does not.
Input

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

The first line of each test case contains a single integer $n$ ($1 \le n \le 2 \cdot 10^5$) — the number of nodes in the tree.

The following $n-1$ lines of each test case contains $2$ integers $a_i$ and $b_i$ ($1 \leq a_i, b_i \leq n, a_i \neq b_i$) — indicating an edge between vertices $a_i$ and $b_i$. It is guaranteed that the given edges form a tree.

It is guaranteed that the sum of $n$ across all test cases does not exceed $2 \cdot 10^5$.

Output

For each test case, print the maximum possible value of any coloring of the tree.

ExampleInput
4
3
1 2
2 3
4
1 2
1 3
1 4
10
1 2
1 3
3 4
3 5
1 6
5 7
2 8
6 9
6 10
1
Output
8
15
96
1
Note

In the first sample, we will color vertex $2$ in $1$ and vertices $1,3$ in $0$. After this, we consider all paths:

  • $(1,1)$ with value $1$
  • $(1,2)$ with value $2$
  • $(1,3)$ with value $2$
  • $(2,2)$ with value $0$
  • $(2,3)$ with value $2$
  • $(3,3)$ with value $1$

We notice the sum of values is $8$ which is the maximum possible.

Input

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Output

题目大意:给定一个包含n个节点的树,你可以将每个节点染成0或1。一条路径(u,v)的价值等于u和v之间最短路径上节点颜色的MEX值。一种染色的价值等于所有路径(u,v)(其中1≤u≤v≤n)的价值之和。求树的任意一种染色的最大可能价值。

输入数据格式:第一行包含一个整数t(1≤t≤10^4),表示测试用例的数量。每个测试用例的第一行包含一个整数n(1≤n≤2×10^5),表示树中节点的数量。接下来n-1行,每行包含两个整数a_i和b_i(1≤a_i,b_i≤n,a_i≠b_i),表示节点a_i和b_i之间有一条边。保证给定的边构成一棵树。所有测试用例的n之和不超过2×10^5。

输出数据格式:对于每个测试用例,输出树的一种染色的最大可能价值。

MEX定义:数组的最小非负整数不属于该数组。例如:
- [2,2,1]的MEX是0,因为0不属于该数组。
- [3,1,0,1]的MEX是2,因为0和1属于该数组,但2不属于。
- [0,3,1,2]的MEX是4,因为0,1,2,3属于该数组,但4不属于。题目大意:给定一个包含n个节点的树,你可以将每个节点染成0或1。一条路径(u,v)的价值等于u和v之间最短路径上节点颜色的MEX值。一种染色的价值等于所有路径(u,v)(其中1≤u≤v≤n)的价值之和。求树的任意一种染色的最大可能价值。 输入数据格式:第一行包含一个整数t(1≤t≤10^4),表示测试用例的数量。每个测试用例的第一行包含一个整数n(1≤n≤2×10^5),表示树中节点的数量。接下来n-1行,每行包含两个整数a_i和b_i(1≤a_i,b_i≤n,a_i≠b_i),表示节点a_i和b_i之间有一条边。保证给定的边构成一棵树。所有测试用例的n之和不超过2×10^5。 输出数据格式:对于每个测试用例,输出树的一种染色的最大可能价值。 MEX定义:数组的最小非负整数不属于该数组。例如: - [2,2,1]的MEX是0,因为0不属于该数组。 - [3,1,0,1]的MEX是2,因为0和1属于该数组,但2不属于。 - [0,3,1,2]的MEX是4,因为0,1,2,3属于该数组,但4不属于。

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