查找可变数量的Ruby数组的产品

Question

我希望从可变数量的数组中找到单个项目的所有组合。我如何在Ruby中做到这一点？

给定两个数组，我可以像这样使用Array.product：

groups = []
groups[0] = ["hello", "goodbye"]
groups[1] = ["world", "everyone"]

combinations = groups[0].product(groups[1])

puts combinations.inspect 
# [["hello", "world"], ["hello", "everyone"], ["goodbye", "world"], ["goodbye", "everyone"]]

当组包含可变数量的数组时，此代码如何工作？

Answer 1

groups = [
  %w[hello goodbye],
  %w[world everyone],
  %w[here there]
]

combinations = groups.first.product(*groups.drop(1))

p combinations
# [
#   ["hello", "world", "here"],
#   ["hello", "world", "there"],
#   ["hello", "everyone", "here"],
#   ["hello", "everyone", "there"],
#   ["goodbye", "world", "here"],
#   ["goodbye", "world", "there"],
#   ["goodbye", "everyone", "here"],
#   ["goodbye", "everyone", "there"]
# ]