A12775 | Path Queries
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内存限制256MB
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题目描述
You are given a weighted tree consisting of $n$ vertices. Recall that a tree is a connected graph without cycles. Vertices $u_i$ and $v_i$ are connected by an edge with weight $w_i$ .
You are given $m$ queries. The $i$ -th query is given as an integer $q_i$ . In this query you need to calculate the number of pairs of vertices $(u, v)$ ( $u < v$ ) such that the maximum weight of an edge on a simple path between $u$ and $v$ doesn't exceed $q_i$ .
You are given $m$ queries. The $i$ -th query is given as an integer $q_i$ . In this query you need to calculate the number of pairs of vertices $(u, v)$ ( $u < v$ ) such that the maximum weight of an edge on a simple path between $u$ and $v$ doesn't exceed $q_i$ .
输入格式
The first line of the input contains two integers $n$ and $m$ ( $1 \le n, m \le 2 \cdot 10^5$ ) — the number of vertices in the tree and the number of queries.
Each of the next $n - 1$ lines describes an edge of the tree. Edge $i$ is denoted by three integers $u_i$ , $v_i$ and $w_i$ — the labels of vertices it connects ( $1 \le u_i, v_i \le n$ , $u_i \ne v_i$ ) and the weight of the edge ( $1 \le w_i \le 2 \cdot 10^5$ ). It is guaranteed that the given edges form a tree.
The last line of the input contains $m$ integers $q_1, q_2, \dots, q_m$ ( $1 \le q_i \le 2 \cdot 10^5$ ), where $q_i$ is the maximum weight of an edge in the $i$ -th query.
Each of the next $n - 1$ lines describes an edge of the tree. Edge $i$ is denoted by three integers $u_i$ , $v_i$ and $w_i$ — the labels of vertices it connects ( $1 \le u_i, v_i \le n$ , $u_i \ne v_i$ ) and the weight of the edge ( $1 \le w_i \le 2 \cdot 10^5$ ). It is guaranteed that the given edges form a tree.
The last line of the input contains $m$ integers $q_1, q_2, \dots, q_m$ ( $1 \le q_i \le 2 \cdot 10^5$ ), where $q_i$ is the maximum weight of an edge in the $i$ -th query.
输出格式
Print $m$ integers — the answers to the queries. The $i$ -th value should be equal to the number of pairs of vertices $(u, v)$ ( $u < v$ ) such that the maximum weight of an edge on a simple path between $u$ and $v$ doesn't exceed $q_i$ .
Queries are numbered from $1$ to $m$ in the order of the input.
Queries are numbered from $1$ to $m$ in the order of the input.
输入输出样例
输入 #1
7 5 1 2 1 3 2 3 2 4 1 4 5 2 5 7 4 3 6 2 5 2 3 4 1
输出 #1
21 7 15 21 3
输入 #2
1 2 1 2
输出 #2
0 0
输入 #3
3 3 1 2 1 2 3 2 1 3 2
输出 #3
1 3 3
The picture shows the tree from the first example: 
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评测结果:Accepted