Question by @Nakilon from 29.07.2021 Thursday.

make_four.rb

# Question by @Nakilon from 29.07.2021 Thursday.

puts "Make an array four times bigger!"

def make_four(array)
  array.map!{|x| x + x}
  (0...array.size).each do |i|
    array.push(array[i])
  end
end


a = [[1]]

make_four(a)

p a

make_four(a)

p a

make_four(a)

p a

puts "Convert an array from a 4 dimensional to a 2 dimensional!"

def four2two(x)
  x.each_with_object(Array.new){ |row,obj|
    obj.push(row.map(&:first).flatten)
    obj.push(row.map(&:last).flatten)
  }
end

four = [
  [
  [[1,2],[3,4]], # element
  [[5,6],[7,8]] # element
  ] # row

      ]
two = four2two(four)

p four
p two

puts "One more example of convertion."

input = [
  [[[1,2],[3,4]],[[5,6],[7,8]]],
  [[[9,10],[11,12]],[[13,14],[15,16]]]
]

output = four2two(input)

p input
p output