Tower of Hanoi

tower_of_hanoi.rb

# tower_of_hanoi.rb

a = [1,2,3,4]
b = []
c = []

# Move the disks from one peg to another following the rules of Hanoi.
#
# number_of_disks - the total number of disks
# from - the starting peg
# to - the ending (goal) peg
# via - the remaining peg (b in this case)
#

def move_disk(number_of_disks,from,to,via)
  if number_of_disks == 1
    to.unshift(from.shift)
  else
    via.unshift(from.shift)
    move_disk(number_of_disks-1, from, to, via)
    to.unshift(via.shift)
  end
  to
end

# here we go!
move_disk(4, a, c, b)
[a,b,c].each {|arr| p arr}