ruby coding challenge

main.rb

class Canvas
  attr_reader :width
  attr_reader :height

  def initialize(input)
    vals = input.split
    @width = vals[0].to_i
    @height = vals[1].to_i
    @all = Array.new(@width * @height, 0)
  end

  def applyPiece(p)
    (p.y .. p.y + p.height - 1).each do |y|
      indexstart = y * @width
      (indexstart + p.x .. indexstart + p.x + p.width - 1).each do |i|
        @all[i] = p.color
      end
    end
  end

  def countColors()
    colors = Hash.new(0)
    @all.each do |x|
      colors[x] += 1
    end
    return colors
  end
end

class Piece
  attr_reader :color
  attr_reader :x
  attr_reader :y
  attr_reader :width
  attr_reader :height

  def initialize(input)
    vals = input.split
    @color = vals[0].to_i
    @x = vals[1].to_i
    @y = vals[2].to_i
    @width = vals[3].to_i
    @height = vals[4].to_i
  end
end


def readInput
  inputs = Array.new
  i = ' '
  loop do
    i = gets.chomp
    break if i.empty?

    inputs.push(i)
  end
  return inputs
end

puts 'Input canvas: width height'
input_canvas = gets.chomp
puts 'Input any pieces in this format: color x y width height'
puts 'Input empty to calculate color occurances.'
inputs = readInput

canvas = Canvas.new(input_canvas)
inputs.each do |i|
  canvas.applyPiece(Piece.new(i))
end

# puts canvas.inspect
col = canvas.countColors
col.keys.sort.each do |k|
  puts('%s %s' % [ k, col[k]])
end