QOJ.ac

QOJ

حد الوقت: 1 s حد الذاكرة: 256 MB مجموع النقاط: 100

#2056. 好基友数

الإحصائيات

Polycarp 认为,如果两个正整数中有一个能被另一个整除,那么它们就是“伙伴”。例如,2 和 4 是伙伴,而 10 和 3 不是。注意,1 与任何正整数都是伙伴。

给定一个整数 $n$,请判断是否可以将从 1 到 $n$ 的所有连续整数排列成一行,使得任意相邻的两个数都是伙伴。如果可以,请输出其中任意一种排列。

输入格式

输入仅一行,包含一个整数 $n$ ($1 \le n \le 1000$)。

输出格式

如果无法按要求排列从 1 到 $n$ 的数字,输出 $-1$。否则,输出任意一种可能的排列,即一行中包含 $n$ 个由空格分隔的整数。如果存在多种可能的排列,输出其中任意一种即可。

样例

样例输入 1

2

样例输出 1

2 1

样例输入 2

3

样例输出 2

3 1 2

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.