查找Ruby中数组的每个排列，包括子数组的排列

本文介绍了查找Ruby中数组的每个排列，包括子数组的排列的处理方法，对大家解决问题具有一定的参考价值，需要的朋友们下面随着小编来一起学习吧！ 问题描述

考虑一个数组:[4, 6, 9]

要求所有排列:(一位，两位和三位数)

Require all the permutations: (one, two and three digit ones)

[[9], [6], [4], [9, 6], [9, 4], [6, 9], [6, 4], [4, 9], [4, 6], [9, 6, 4], [9, 4, 6], [6, 9, 4], [6, 4, 9], [4, 9, 6], [4, 6, 9]]

推荐答案

记录此问题和我自己的发现，因为我在搜索时没有找到足够简单的东西.也许这可以帮助某人:

Recording this question and my own finding as I didn't find anything simple enough while searching. Perhaps this may help someone:

a = [4, 6, 9] (1..a.length).flat_map { |n| a.permutation(n).to_a }

对于每种组合，只需切换方法，如下所示:

And for every combination, just switch the method, like so:

a = [4, 6, 9] (1..a.length).flat_map { |n| abination(n).to_a }