Ehab and a weird weight formula

2000ms

262144K

Description:

You're given a tree consisting of $$$n$$$ nodes. Every node $$$u$$$ has a weight $$$a_u$$$. It is guaranteed that there is only one node with minimum weight in the tree. For every node $$$u$$$ (except for the node with the minimum weight), it must have a neighbor $$$v$$$ such that $$$a_v<a_u$$$. You should construct a tree to minimize the weight $$$w$$$ calculated as follows:

For every node $$$u$$$, $$$deg_u \cdot a_u$$$ is added to $$$w$$$ ($$$deg_u$$$ is the number of edges containing node $$$u$$$).
For every edge $$$\{ u,v \}$$$, $$$\lceil log_2(dist(u,v)) \rceil \cdot min(a_u,a_v)$$$ is added to $$$w$$$, where $$$dist(u,v)$$$ is the number of edges in the path from $$$u$$$ to $$$v$$$ in the given tree.

Input:

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

The second line contains $$$n$$$ space-separated integers $$$a_1, a_2, \ldots, a_n$$$ $$$(1 \le a_i \le 10^9)$$$, the weights of the nodes.

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

Output:

Output one integer, the minimum possible value for $$$w$$$.

Sample Input:

Sample Output:

Sample Input:

Sample Output:

Note:

In the first sample, the tree itself minimizes the value of $$$w$$$.

In the second sample, the optimal tree is:

$\text{[math]}$

Informação

Provedor Codeforces

Código CF1088F