VK Cup 2015 - Finals, online mirror
C
Logistical Questions
Codeforces
3000
原题
← BD →
翻译中…

Some country consists of $*n*$ cities, connected by a railroad network. The transport communication of the country is so advanced that the network consists of a minimum required number of $(*n* - 1)$ bidirectional roads (in the other words, the graph of roads is a tree). The $*i*$-th road that directly connects cities $*a*_{*i*}$ and $*b*_{*i*}$, has the length of $*l*_{*i*}$ kilometers.

翻译中…

The transport network is served by a state transporting company FRR (Fabulous Rail Roads). In order to simplify the price policy, it offers a single ride fare on the train. In order to follow the route of length $*t*$ kilometers, you need to pay image burles. Note that it is forbidden to split a long route into short segments and pay them separately (a special railroad police, or RRP, controls that the law doesn't get violated).

翻译中…

A Large Software Company decided to organize a programming tournament. Having conducted several online rounds, the company employees determined a list of finalists and sent it to the logistical department to find a place where to conduct finals. The Large Software Company can easily organize the tournament finals in any of the $*n*$ cities of the country, so the the main factor in choosing the city for the last stage of the tournament is the total cost of buying tickets for all the finalists. We know that the $*i*$-th city of the country has $*w*_{*i*}$ cup finalists living there.

翻译中…

Help the company employees find the city such that the total cost of travel of all the participants to it is minimum.

翻译中…

Input

翻译中…

The first line of the input contains number $*n*$ ($1 ≤ *n* ≤ 200 000$) — the number of cities in the country.

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The next line contains $*n*$ integers $*w*_{1}, *w*_{2}, ..., *w*_{*n*}$ ($0 ≤ *w*_{*i*} ≤ 10^{8}$) — the number of finalists living in each city of the country.

翻译中…

Next $(*n* - 1)$ lines contain the descriptions of the railroad, the $*i*$-th line contains three integers, $*a*_{*i*}$, $*b*_{*i*}$, $*l*_{*i*}$ ($1 ≤ *a*_{*i*}, *b*_{*i*} ≤ *n*$, $*a*_{*i*} ≠ *b*_{*i*}$, $1 ≤ *l*_{*i*} ≤ 1000$).

翻译中…

Output

翻译中…

Print two numbers — an integer $*f*$ that is the number of the optimal city to conduct the competition, and the real number $*c*$, equal to the minimum total cost of transporting all the finalists to the competition. Your answer will be considered correct if two conditions are fulfilled at the same time:

翻译中…
  1. The absolute or relative error of the printed number $*c*$ in comparison with the cost of setting up a final in city $*f*$ doesn't exceed $10^{ - 6}$;
  2. Absolute or relative error of the printed number $*c*$ in comparison to the answer of the jury doesn't exceed $10^{ - 6}$.
翻译中…

If there are multiple answers, you are allowed to print any of them.

翻译中…

Note

翻译中…

In the sample test an optimal variant of choosing a city to conduct the finals of the competition is $3$. At such choice the cost of conducting is image burles.

翻译中…

In the second sample test, whatever city you would choose, you will need to pay for the transport for five participants, so you will need to pay image burles for each one of them.

翻译中…

样例

Input #1
5
3 1 2 6 5
1 2 3
2 3 1
4 3 9
5 3 1
Output #1
3 192.0
InputCopy OutputCopy
Input #2
2
5 5
1 2 2
Output #2
1 14.142135623730951000
InputCopy OutputCopy
题目信息
题号
566C
时间限制
2 s
内存限制
256 MB
标签
DFS 及类似
分治
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。