apuzzle-83.rb

apuzzle-83.rb

def out(from, to, k)
  $state[to - 1] += 1
  $state[from - 1] -= 1
  puts "[#{k}]: #{from} -> #{to}, #{$state}"
end

def move_2_to_3(k)
  return if k == 0
  move_2_to_1(k - 1)
  out(2, 3, k)
  move_1_to_2(k - 1)
  move_2_to_3(k - 1)
end

def move_2_to_1(k)
  return if k == 0
  move_2_to_3(k - 1)
  out(2, 1, k)
  move_3_to_2(k - 1)
  move_2_to_1(k - 1)
end

def move_1_to_2(k)
  return if k == 0
  move_1_to_2(k - 1)
  move_2_to_3(k - 1)
  out(1, 2, k)
  move_3_to_2(k - 1)
end

def move_2_to_3(k)
  return if k == 0
  move_2_to_1(k - 1)
  out(2, 3, k)
  move_1_to_2(k - 1)
  move_2_to_3(k - 1)
end

def move_3_to_2(k)
  return if k == 0
  move_3_to_2(k - 1)
  move_2_to_1(k - 1)
  out(3, 2, k)
  move_1_to_2(k - 1)
end

def move_1_to_3(k)
  return if k == 0
  move_1_to_2(k - 1)
  move_2_to_3(k - 1)
  out(1, 2, k)
  move_3_to_2(k - 1)
  move_2_to_1(k - 1)
  out(2, 3, k)
  move_1_to_2(k - 1)
  move_2_to_3(k - 1)
end

count = 4
$state = [count, 0, 0]
move_1_to_3(count)