AtCoder Beginner Contest 146
D
Coloring Edges on Tree
AtCoder
⌀ 1192
原题
← CE →
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Problem Statement

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Given is a tree $G$ with $N$ vertices. The vertices are numbered $1$ through $N$, and the $i$-th edge connects Vertex $a_i$ and Vertex $b_i$.

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Consider painting the edges in $G$ with some number of colors. We want to paint them so that, for each vertex, the colors of the edges incident to that vertex are all different.

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Among the colorings satisfying the condition above, construct one that uses the minimum number of colors.

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Constraints

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  • $2 \le N \le 10^5$
  • $1 \le a_i \lt b_i \le N$
  • All values in input are integers.
  • The given graph is a tree.
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Input

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Input is given from Standard Input in the following format:

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N
a_1 b_1
a_2 b_2
\vdots
a_{N-1} b_{N-1}

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Output

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Print $N$ lines.

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The first line should contain $K$, the number of colors used.

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The $(i+1)$-th line $(1 \le i \le N-1)$ should contain $c_i$, the integer representing the color of the $i$-th edge, where $1 \le c_i \le K$ must hold.

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If there are multiple colorings with the minimum number of colors that satisfy the condition, printing any of them will be accepted.

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样例

Input #1
3
1 2
2 3
Output #1
2
1
2
Input #2
8
1 2
2 3
2 4
2 5
4 7
5 6
6 8
Output #2
4
1
2
3
4
1
1
2
Input #3
6
1 2
1 3
1 4
1 5
1 6
Output #3
5
1
2
3
4
5
题目信息
题号
abc146_d
时间限制
2 s
内存限制
1024 MB

题面与样例版权归 AtCoder 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。