A13433. Edge Weight Assignment
编程题
普及/提高-
知识点
题目描述
You have unweighted tree of $n$ vertices. You have to assign a positive weight to each edge so that the following condition would hold:
- For every two different leaves $v_{1}$ and $v_{2}$ of this tree, [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of weights of all edges on the simple path between $v_{1}$ and $v_{2}$ has to be equal to $0$ .
Note that you can put very large positive integers (like $10^{(10^{10})}$ ).
It's guaranteed that such assignment always exists under given constraints. Now let's define $f$ as the number of distinct weights in assignment.
 In this example, assignment is valid, because bitwise XOR of all edge weights between every pair of leaves is $0$ . $f$ value is $2$ here, because there are $2$ distinct edge weights( $4$ and $5$ ). In this example, assignment is invalid, because bitwise XOR of all edge weights between vertex $1$ and vertex $6$ ( $3, 4, 5, 4$ ) is not $0$ .
What are the minimum and the maximum possible values of $f$ for the given tree? Find and print both.
- For every two different leaves $v_{1}$ and $v_{2}$ of this tree, [bitwise XOR](https://en.wikipedia.org/wiki/Bitwise_operation#XOR) of weights of all edges on the simple path between $v_{1}$ and $v_{2}$ has to be equal to $0$ .
Note that you can put very large positive integers (like $10^{(10^{10})}$ ).
It's guaranteed that such assignment always exists under given constraints. Now let's define $f$ as the number of distinct weights in assignment.
 In this example, assignment is valid, because bitwise XOR of all edge weights between every pair of leaves is $0$ . $f$ value is $2$ here, because there are $2$ distinct edge weights( $4$ and $5$ ). In this example, assignment is invalid, because bitwise XOR of all edge weights between vertex $1$ and vertex $6$ ( $3, 4, 5, 4$ ) is not $0$ .
What are the minimum and the maximum possible values of $f$ for the given tree? Find and print both.
输入格式
The first line contains integer $n$ ( $3 \le n \le 10^{5}$ ) — the number of vertices in given tree.
The $i$ -th of the next $n-1$ lines contains two integers $a_{i}$ and $b_{i}$ ( $1 \le a_{i} \lt b_{i} \le n$ ) — it means there is an edge between $a_{i}$ and $b_{i}$ . It is guaranteed that given graph forms tree of $n$ vertices.
The $i$ -th of the next $n-1$ lines contains two integers $a_{i}$ and $b_{i}$ ( $1 \le a_{i} \lt b_{i} \le n$ ) — it means there is an edge between $a_{i}$ and $b_{i}$ . It is guaranteed that given graph forms tree of $n$ vertices.
输出格式
Print two integers — the minimum and maximum possible value of $f$ can be made from valid assignment of given tree. Note that it's always possible to make an assignment under given constraints.
输入输出样例
输入 #1
6 1 3 2 3 3 4 4 5 5 6
输出 #1
1 4
输入 #2
6 1 3 2 3 3 4 4 5 4 6
输出 #2
3 3
输入 #3
7 1 2 2 7 3 4 4 7 5 6 6 7
输出 #3
1 6
说明/提示
In the first example, possible assignments for each minimum and maximum are described in picture below. Of course, there are multiple possible assignments for each minimum and maximum.
In the second example, possible assignments for each minimum and maximum are described in picture below. The $f$ value of valid assignment of this tree is always $3$ .
In the third example, possible assignments for each minimum and maximum are described in picture below. Of course, there are multiple possible assignments for each minimum and maximum.
In the second example, possible assignments for each minimum and maximum are described in picture below. The $f$ value of valid assignment of this tree is always $3$ .
In the third example, possible assignments for each minimum and maximum are described in picture below. Of course, there are multiple possible assignments for each minimum and maximum.
