RosettaCodeData/Task/Numbers-with-equal-rises-and-falls/Ruby/numbers-with-equal-rises-and-falls.rb
2023-07-01 13:44:08 -04:00

9 lines
284 B
Ruby

class Integer
def eq_rise_fall? = digits.each_cons(2).sum{|a,b| a <=> b} == 0
end
puts (1..).lazy.select(&:eq_rise_fall?).take(200).force.join(" ")
n = 10_000_000
res = (1..).lazy.select(&:eq_rise_fall?).take(n).drop(n-1).first
puts "The #{n}th number in the sequence is #{res}."