CODEWITHSUNDEEP
rubysortingarrays
Shreyas
Shreyas

Reputation: 8757

In Ruby how do you sort one multi dimendional array by another multi dimensional array?

Lets say I have an array : a=[[1,2,3],[4,5]] and I have another array : b=[[2.5,1.5,3.5],[1.5,2.5]]

I need to sort 'a' with respect to 'b'. i.e the output should be = [[3,1,2],[5,4]]

I tried but my code seemed to be very lengthy. It would be great if you could help me out.Thanks!

Upvotes: 4

Views: 333

Answers (2)

Marc-André Lafortune
Marc-André Lafortune

Reputation: 79562

Next time, it would be a great idea to post your code, and an explanation of the context can also be handy.

Here's a way to get your desired results

a.zip(b).map do |values, sort_values|
  sort_values.zip(values).sort.reverse_each.map{|sort, value| value}
end

Upvotes: 1

sepp2k
sepp2k

Reputation: 370162

This gives your sample output for your sample input, so hopefully it's what you want (it sorts the values of each subarray in the first array by the value at the same position in the corresponding subarray of the second array, descendingly):

class Array
  def sort_by_other_array(arr)
    zip(arr).sort_by {|x,y| y}.map {|x,y| x}
  end
end

a=[[1,2,3],[4,5]]
b=[[2.5,1.5,3.5],[1.5,2.5]]
a.zip(b).map {|x,y| x.sort_by_other_array(y).reverse}
#=> [[3, 1, 2], [5, 4]]

Upvotes: 3

Related Questions