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ruby: compare two arrays

Added by over 3 years ago

I want to know whether the array A contains the array B.

Ruby doesnot support array comparision so we neeed some maths.:

B \subset A  <=>  { B \ (A \cap B) == \emptyset }

Now define the following function

class Array
  def subset?(a)
    (self - (self & a)).empty?

and test it

  [1,2].subset? [1,2,3] => true
[1,2,3].subset? [1,2]   => false

It works :)