Codeforces Round 722 (Div. 1)
A
Parsa's Humongous Tree
Codeforces
1600
原题
←B →
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Parsa has a humongous tree on $n$ vertices.

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On each vertex $v$ he has written two integers $l_v$ and $r_v$.

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To make Parsa's tree look even more majestic, Nima wants to assign a number $a_v$ ($l_v \le a_v \le r_v$) to each vertex $v$ such that the beauty of Parsa's tree is maximized.

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Nima's sense of the beauty is rather bizarre. He defines the beauty of the tree as the sum of $|a_u - a_v|$ over all edges $(u, v)$ of the tree.

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Since Parsa's tree is too large, Nima can't maximize its beauty on his own. Your task is to find the maximum possible beauty for Parsa's tree.

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Input

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The first line contains an integer $t$ $(1\le t\le 250)$ — the number of test cases. The description of the test cases follows.

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The first line of each test case contains a single integer $n$ $(2\le n\le 10^5)$ — the number of vertices in Parsa's tree.

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The $i$-th of the following $n$ lines contains two integers $l_i$ and $r_i$ $(1 \le l_i \le r_i \le 10^9)$.

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Each of the next $n-1$ lines contains two integers $u$ and $v$ $(1 \le u , v \le n, u\neq v)$ meaning that there is an edge between the vertices $u$ and $v$ in Parsa's tree.

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It is guaranteed that the given graph is a tree.

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It is guaranteed that the sum of $n$ over all test cases doesn't exceed $2 \cdot 10^5$.

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Output

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For each test case print the maximum possible beauty for Parsa's tree.

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Note

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The trees in the example:

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image

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In the first test case, one possible assignment is $a = \{1, 8\}$ which results in $|1 - 8| = 7$.

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In the second test case, one of the possible assignments is $a = \{1, 5, 9\}$ which results in a beauty of $|1 - 5| + |5 - 9| = 8$

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样例

Input #1
3
2
1 6
3 8
1 2
3
1 3
4 6
7 9
1 2
2 3
6
3 14
12 20
12 19
2 12
10 17
3 17
3 2
6 5
1 5
2 6
4 6
Output #1
7
8
62
InputCopy OutputCopy
题目信息
题号
1528A
时间限制
1 s
内存限制
256 MB
标签
DFS 及类似
分治
动态规划
贪心
树

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