AF - Codility: Task2

af2_original_submission.rb

  def solution(a)
    total = a.size
    lindex = a.size-1
    sorted = a.sort
    min = total
    combos = []

    return 0 if a == sorted

    (2..total).each do |pair_size|
      (0..lindex).each_cons(pair_size) { |range| combos << range }
    end

    combos.each do |range|
      duped = a.dup
      duped[range.first..range.last] = a[range.first..range.last].sort
      if duped == sorted
        min = (range.size < min ) ? range.size : min
        return min if min == 2
      end
    end

    min
  end

af2_refactored.rb

  def solution(a)
    total = a.size
    lindex = a.size-1
    sorted = a.sort
    min = total

    return 0 if a == sorted

    (2..total).each do |pair_size|
      (0..lindex).each_cons(pair_size) do |range|
        duped = a.dup
        duped[range.first..range.last] = a[range.first..range.last].sort
        return range.size if duped == sorted # preemptively return before trying larger index ranges. We only need the min
      end
    end

    min
  end