阵列的所有组合 [英] All combinations of array

问题描述

我有数组

  A = [W1，W2，W3]
 

我怎样才能生成一个新的数组值的每个组合？ 我需要的输出是这样的：

  [W1，W2，W3，W1 W1，W1 W2，W1 W3，W2 W1，W2 W2， W2 W3，W3 W1，W3 W2，W3 W3，W1 W1 W1，W1 W1 W2，W1 W1 W3，W1 W2 W1，W1 W2 W2， W1 W2 W3，W2 W1 W1，W2 W1 W2，W2 W1 W2，W2 W1 W3，W2 W2 W1，W2 W2 W2，W2 W2 W3，W2 W3 W1，W2 W3 W2，W2 W3 W3，W3 W1 W1，W3 W1 W2，W3 W1 W3，W3 W2 W1，W3 W2 W2，W3 W2 W3 ，W3 W3 W1，W3 W3 W2，W3 W3 W2]
 

从<一个

尝试code href="http://stackoverflow.com/questions/10900636/generate-array-of-all-combinations-of-an-existing-array">Generate现有阵列的所有组合的阵列

结果不正确

 W1，W2，W3，W1 W2，W1 W3，W2 W3，W1 W2 W3]
 

解决方案

下面是做到这一点的一种方式，但这样的结果有W3 W3 W3和你想要的结果没有，但我看不出逻辑，包括W3 W3和W1 W1 W1，而不是W3 W3 W3，所以我以为你只是错过补充说。

您正在寻找的是不是组合，但排列（与repetation）：

  A = [W1，W2，W3]

结果=（1..a.size）.flat_map办|大小|
  a.repeated_permutation（尺寸）.MAP {|烫发| perm.join（''）}
结束
 

I have array

a = ["w1", "w2", "w3"]

How can I generate a new array with every combination of values? I need the output to look like this:

["w1", "w2", "w3", "w1 w1", "w1 w2", "w1 w3", "w2 w1", "w2 w2", "w2 w3", "w3 w1", "w3 w2", "w3 w3", "w1 w1 w1", "w1 w1 w2", "w1 w1 w3", "w1 w2 w1", "w1 w2 w2", "w1 w2 w3", "w2 w1 w1", "w2 w1 w2", "w2 w1 w2", "w2 w1 w3", "w2 w2 w1", "w2 w2 w2", "w2 w2 w3", "w2 w3 w1", "w2 w3 w2", "w2 w3 w3", "w3 w1 w1", "w3 w1 w2", "w3 w1 w3", "w3 w2 w1", "w3 w2 w2", "w3 w2 w3", "w3 w3 w1", "w3 w3 w2", "w3 w3 w2"]

Try code from Generate array of all combinations of an existing array

Result incorrect

"w1", "w2", "w3", "w1 w2", "w1 w3", "w2 w3", "w1 w2 w3"]

解决方案

Here is one way to do it, however this result has "w3 w3 w3" and you desired result does not, but I do not see the logic to include "w3 w3" and "w1 w1 w1" but not "w3 w3 w3", so I assume you just missed to add that.

What you are looking for is not the combinations, but the permutations (with repetation):

a = ["w1", "w2", "w3"]

result = (1..a.size).flat_map do |size|
  a.repeated_permutation(size).map { |perm| perm.join(' ') }
end

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