The Clocks problem (implemented in Ruby)

clocks_problem.rb

##########################################################################
# Problem: The Clocks problem
# Description: suppose you have 2 clocks with the following conditions:
#   + one clock put forward one minute each hour; and
#   + the other clock put back one minute each hour
# Having both clocks showing the same time, the question is:
#   + how long we should wait until they show the same time again?
#
# Solution by Ariel Diaz Bermejo

class Clock
  attr_accessor :hours, :minutes

  def initialize(hours,minutes)
    @hours,@minutes = hours,minutes
  end

  def ==(clock)
    (self.hours == clock.hours) && (self.minutes == clock.minutes)
  end

  def advance(mins)
    added_hs = (mins/60)
    added_mins = (mins % 60)

    mins_remain = 60-self.minutes # Mins remaining until reset minutes
    hs_remain   = 12-self.hours # Hs remaining until reset hour

    added_hs += 1 if added_mins >= mins_remain

    # Adding minutes
    self.minutes = (added_mins < mins_remain) ? (self.minutes+added_mins) : (added_mins - mins_remain)
    # Adding hours
    self.hours = (added_hs < hs_remain) ? (self.hours+added_hs) : (added_hs - hs_remain)
  end

  def to_s
    "#{self.hours}:#{self.minutes}"
  end

end

# Instantiates 2 clocks with the same time
clock_1 = Clock.new(0,0)
clock_2 = Clock.new(0,0)
puts "We are creating 2 clocks showing the same hour:"
puts "\tClock 1: #{clock_1}"
puts "\tClock 2: #{clock_2}"
puts "Now we're advancing the first clock 61 minutes and the second 59 minutes"
puts "and we wait until they show the same hour again..."

# We're going to advance one clock
1000.times do |i|
  clock_1.advance(61)
  clock_2.advance(59)
  if clock_1 == clock_2
    i += 1 # incrementing i because it starts with zero (0) instead of one (1)
    puts "Clocks show same hour after #{i/24} days and #{i%24} hours" 
    puts "\tClock 1: #{clock_1}"
    puts "\tClock 2: #{clock_2}"
    break
  end
end