covering_segments.rb

#!/usr/bin/env ruby
# by Andronik Ordian
# updated by Jeffrey Matthias

Segment = Struct.new("Segment", :start, :end)

def optimal_points(segments)
  points = []
  return points if segments.empty?
  #write your code here

  points
end

if __FILE__ == $0
  number_of_segments = gets.chomp.to_i
  segments = []
  number_of_segments.times do
    start, finish = gets.chomp.split.map(&:to_i)
    segments << Segment.new(start, finish)
  end
  points = optimal_points(segments)
  puts "#{points.size}"
  puts "#{points.join(' ')}"
end