Ugly Numbers Challenge

ugly_numbers.rb

class Numeric
  def ugly?
    self == 0 || self % 2 == 0 || self % 3 == 0 || self % 5 == 0 || self % 7 == 0
  end
end

# lines.each do |line|

orig_arr = line.strip.split(//)
line_arr = line.strip.gsub(/(0+)/, "0").split(//) # replace multiple zeros with one (for speed)
missing_zeros = orig_arr.length - line_arr.length

# perm_count = 3**(line_arr.length - 1)

# All permutations of operators
ops = []
["","-","+"].repeated_permutation(line_arr.length - 1) { |p| ops << p }

numbers = []
ops.each do |op_arr|
  # zip interleaves into multiple arrays then flatten and join into a sinle line again
  l = line_arr.zip(op_arr).flatten.join
  if l == "0"
    new_line = "0"
  else
    # Remove all leading zeros, remove all zeros that follow a + or a - and remove any trailing + or -
    new_line = l.gsub(/\A(0+)/, "").gsub(/\+(0+)/, "+").gsub(/\-(0+)/, "-").gsub(/(\-\z)|(\+\z)/, "")
  end
  numbers << eval(new_line)
end

# Count the uglies
ugly_count = 0
numbers.each do |n|
  ugly_count +=1 if n.ugly?
end

puts "#{line}-#{ugly_count}"
puts ugly_count * 3**missing_zeros

end