arrayproblem.rb

require 'pry'

# You're given a vector of vectors of words, e.g.:
# [['quick', 'lazy'], ['brown', 'black', 'grey'], ['fox', 'dog']].
#
# Write a generalized function that prints all combinations of one word from the first vector, one word from the second vector, etc.
# The solution may not use recursion.
#
# NOTE: the *number of vectors* and number of elements within each vector may vary.

class ArrayThingy
  attr_reader :array

  def initialize(array)
    @array = array
    @array_point_map = array_start_length_map
    @combos = []
  end

  def array_combos
    array_count = 0
    new_combo = []
    while @combos.length < total_combo_count
      new_combo << array[array_count][@array_point_map[array_count]]
      if new_combo.length == array.length
        @combos << new_combo
        new_combo = []
        array_count = 0
        update_counter_map
      else
        array_count += 1
      end
    end
    print_combos
  end

  def total_combo_count
    count = 1
    array.each do |subarray|
      count = count * subarray.length
    end
    count
  end

  def array_end_length_map
    array.map { |sub_array| sub_array.length }
  end

  def array_start_length_map
    array.map { |sub_array| 0 }
  end

  def update_counter_map
    checking = true
    counter = 0
    while checking && counter < array.length
      if @array_point_map[counter] == array_end_length_map[counter] - 1
        @array_point_map[counter] = 0
        counter += 1
      else
        @array_point_map[counter] += 1
        checking = false
      end
    end
  end

  def print_combos
    @combos.each do |combo|
      puts combo.join(" ")
    end
  end
end

array = ArrayThingy.new([['quick', 'lazy'], ['brown', 'black', 'grey'], ['fox', 'dog']])

array.array_combos