CF1088F.Ehab and a weird weight formula

普及/提高-

通过率:0%

AC君温馨提醒

该题目为【codeforces】题库的题目,您提交的代码将被提交至codeforces进行远程评测,并由ACGO抓取测评结果后进行展示。由于远程测评的测评机由其他平台提供,我们无法保证该服务的稳定性,若提交后无反应,请等待一段时间后再进行重试。

题目描述

You're given a tree consisting of nn nodes. Every node uu has a weight aua_u . It is guaranteed that there is only one node with minimum weight in the tree. For every node uu (except for the node with the minimum weight), it must have a neighbor vv such that av<aua_v<a_u . You should construct a tree to minimize the weight ww calculated as follows:

  • For every node uu , deguaudeg_u \cdot a_u is added to ww ( degudeg_u is the number of edges containing node uu ).
  • For every edge {u,v}\{ u,v \} , log2(dist(u,v))min(au,av)\lceil log_2(dist(u,v)) \rceil \cdot min(a_u,a_v) is added to ww , where dist(u,v)dist(u,v) is the number of edges in the path from uu to vv in the given tree.

输入格式

The first line contains the integer nn (2n5105)(2 \le n \le 5 \cdot 10^5) , the number of nodes in the tree.

The second line contains nn space-separated integers a1,a2,,ana_1, a_2, \ldots, a_n (1ai109)(1 \le a_i \le 10^9) , the weights of the nodes.

The next n1n-1 lines, each contains 2 space-separated integers uu and vv (1u,vn)(1 \le u,v \le n) which means there's an edge between uu and vv .

输出格式

Output one integer, the minimum possible value for ww .

输入输出样例

  • 输入#1

    3
    1 2 3
    1 2
    1 3
    

    输出#1

    7
  • 输入#2

    5
    4 5 3 7 8
    1 2
    1 3
    3 4
    4 5
    

    输出#2

    40

说明/提示

In the first sample, the tree itself minimizes the value of ww .

In the second sample, the optimal tree is:

首页