Codeforces Round 362 (Div. 1)
B
Puzzles
Codeforces
1700
原题
← AC →
翻译中…

Barney lives in country USC (United States of Charzeh). USC has $*n*$ cities numbered from $1$ through $*n*$ and $*n* - 1$ roads between them. Cities and roads of USC form a rooted tree (Barney's not sure why it is rooted). Root of the tree is the city number $1$. Thus if one will start his journey from city $1$, he can visit any city he wants by following roads.

翻译中…

image

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Some girl has stolen Barney's heart, and Barney wants to find her. He starts looking for in the root of the tree and (since he is Barney Stinson not a random guy), he uses a random DFS to search in the cities. A pseudo code of this algorithm is as follows:

翻译中…

let starting_time be an array of length n
current_time = 0
dfs(v):
	current_time = current_time + 1
	starting_time[v] = current_time
	shuffle children[v] randomly (each permutation with equal possibility)
	// children[v] is vector of children cities of city v
	for u in children[v]:
		dfs(u)

翻译中…

As told before, Barney will start his journey in the root of the tree (equivalent to call dfs(1)).

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Now Barney needs to pack a backpack and so he wants to know more about his upcoming journey: for every city $*i*$, Barney wants to know the expected value of starting_time[i]. He's a friend of Jon Snow and knows nothing, that's why he asked for your help.

翻译中…

Input

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The first line of input contains a single integer $*n*$ ($1 ≤ *n* ≤ 10^{5}$) — the number of cities in USC.

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The second line contains $*n* - 1$ integers $*p*_{2}, *p*_{3}, ..., *p*_{*n*}$ ($1 ≤ *p*_{*i*} < *i*$), where $*p*_{*i*}$ is the number of the parent city of city number $*i*$ in the tree, meaning there is a road between cities numbered $*p*_{*i*}$ and $*i*$ in USC.

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Output

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In the first and only line of output print $*n*$ numbers, where $*i*$-th number is the expected value of starting_time[i].

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Your answer for each city will be considered correct if its absolute or relative error does not exceed $10^{ - 6}$.

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样例

Input #1
7
1 2 1 1 4 4
Output #1
1.0 4.0 5.0 3.5 4.5 5.0 5.0
InputCopy OutputCopy
Input #2
12
1 1 2 2 4 4 3 3 1 10 8
Output #2
1.0 5.0 5.5 6.5 7.5 8.0 8.0 7.0 7.5 6.5 7.5 8.0
InputCopy OutputCopy
题目信息
题号
696B
时间限制
1 s
内存限制
256 MB
标签
DFS 及类似
数学
概率论
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。