查找Ruby中数组的每个排列，包括子数组的排列 [英] Find every permutation of an array in Ruby, including permutations with sub arrays

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| a.combination(n).to_a }

这篇关于查找Ruby中数组的每个排列，包括子数组的排列的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！