QOJ.ac

QOJ

実行時間制限: 2.0 s メモリ制限: 256 MB 満点: 100

#18503. 图着色

統計

给定一个无向图,其中每个顶点的度数最多为 $5$。请用 $3$ 种颜色为它的顶点染色,使得每个顶点 $v$ 最多只有一个与其颜色相同的邻居。

输入格式

第一行包含两个整数 $n$ 和 $m$:顶点数和边数($1 \le n \le 100\,000$)。

接下来的 $m$ 行,每行包含两个整数 $a$ 和 $b$:由一条边连接的两个顶点的编号($1 \le a, b \le n$)。

保证图中无自环和重边,且每个顶点的度数最多为 $5$。

输出格式

如果不存在合法的染色方案,输出一个数字 “-1”(不含引号)。否则,输出 $n$ 个整数 $c_1, c_2, \dots, c_n$:所有顶点的颜色($1 \le c_i \le 3$)。如果存在多种方案,输出其中任意一种即可。

样例

输入样例 1

3 3
1 2
2 3
1 3

输出样例 1

2 1 1

输入样例 2

6 15
1 2
1 3
1 4
1 5
1 6
2 3
2 4
2 5
2 6
3 4
3 5
3 6
4 5
4 6
5 6

输出样例 2

2 2 3 3 1 1

输入样例 3

3 1
1 2

输出样例 3

1 1 1

Discussions

About Discussions

The discussion section is only for posting: General Discussions (problem-solving strategies, alternative approaches), and Off-topic conversations.

This is NOT for reporting issues! If you want to report bugs or errors, please use the Issues section below.

Open Discussions 0
No discussions in this category.

Issues

About Issues

If you find any issues with the problem (statement, scoring, time/memory limits, test cases, etc.), you may submit an issue here. A problem moderator will review your issue.

Guidelines:

  1. This is not a place to publish discussions, editorials, or requests to debug your code. Issues are only visible to you and problem moderators.
  2. Do not submit duplicated issues.
  3. Issues must be filed in English or Chinese only.
Active Issues 0
No issues in this category.
Closed/Resolved Issues 0
No issues in this category.