Codeforces Round 646 (Div. 2)
E
Tree Shuffling
Codeforces
2000
原题
← DF →
翻译中…

Ashish has a tree consisting of $n$ nodes numbered $1$ to $n$ rooted at node $1$. The $i$-th node in the tree has a cost $a_i$, and binary digit $b_i$ is written in it. He wants to have binary digit $c_i$ written in the $i$-th node in the end.

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To achieve this, he can perform the following operation any number of times:

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  • Select any $k$ nodes from the subtree of any node $u$, and shuffle the digits in these nodes as he wishes, incurring a cost of $k \cdot a_u$. Here, he can choose $k$ ranging from $1$ to the size of the subtree of $u$.
翻译中…

He wants to perform the operations in such a way that every node finally has the digit corresponding to its target.

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Help him find the minimum total cost he needs to spend so that after all the operations, every node $u$ has digit $c_u$ written in it, or determine that it is impossible.

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Input

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First line contains a single integer $n$ $(1 \le n \le 2 \cdot 10^5)$ denoting the number of nodes in the tree.

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$i$-th line of the next $n$ lines contains 3 space-separated integers $a_i$, $b_i$, $c_i$ $(1 \leq a_i \leq 10^9, 0 \leq b_i, c_i \leq 1)$  — the cost of the $i$-th node, its initial digit and its goal digit.

翻译中…

Each of the next $n - 1$ lines contain two integers $u$, $v$ $(1 \leq u, v \leq n, \text{ } u \ne v)$, meaning that there is an edge between nodes $u$ and $v$ in the tree.

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Output

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Print the minimum total cost to make every node reach its target digit, and $-1$ if it is impossible.

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Note

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The tree corresponding to samples $1$ and $2$ are:

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image

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In sample $1$, we can choose node $1$ and $k = 4$ for a cost of $4 \cdot 1$ = $4$ and select nodes ${1, 2, 3, 5}$, shuffle their digits and get the desired digits in every node.

翻译中…

In sample $2$, we can choose node $1$ and $k = 2$ for a cost of $10000 \cdot 2$, select nodes ${1, 5}$ and exchange their digits, and similarly, choose node $2$ and $k = 2$ for a cost of $2000 \cdot 2$, select nodes ${2, 3}$ and exchange their digits to get the desired digits in every node.

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In sample $3$, it is impossible to get the desired digits, because there is no node with digit $1$ initially.

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样例

Input #1
5
1 0 1
20 1 0
300 0 1
4000 0 0
50000 1 0
1 2
2 3
2 4
1 5
Output #1
4
InputCopy OutputCopy
Input #2
5
10000 0 1
2000 1 0
300 0 1
40 0 0
1 1 0
1 2
2 3
2 4
1 5
Output #2
24000
InputCopy OutputCopy
Input #3
2
109 0 1
205 0 1
1 2
Output #3
-1
InputCopy OutputCopy
题目信息
题号
1363E
时间限制
2 s
内存限制
256 MB
标签
DFS 及类似
动态规划
贪心
树

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。