Pasted

 
 
$n = 11
 
​
 
$towers = {}
 
​
 
$idx = {a: 1, b: 2, c: 3}
 
​
 
def init
 
  $towers = {
 
    a: 1.upto($n).to_a.reverse,
 
    b: [],
 
    c: []
 
  }
 
end
 
​
 
init()
 
​
 
def stat()
 
  ts = [:a, :b, :c]
 
  puts ts.join("\t")
 
  ($n - 1).downto(0).each do |i|
 
    [:a, :b, :c].each do |t|
 
      print "#{$towers[t][i]}\t"
 
    end
 
    puts
 
  end
 
end
 
​
 
def m(from, to)
 
  d = $towers[from].pop
 
  dest_d = $towers[to].last
 
  if (to == :b && d == 1) || (dest_d && d > dest_d)
 
    puts("illegal move")
 
    exit(0)
 
  end
 
  $towers[to].push(d)
 
  puts "#{d} #{$idx[from]} #{$idx[to]}"
 
end
 
​
 
​
 
def move_right
 
  m(:a,:c)
 
  m(:a,:b)
 
  m(:c,:a)
 
  m(:b,:c)
 
  m(:a,:c)
 
end
 
​
 
def move_left
 
  m(:c,:a)
 
  m(:c,:b)
 
  m(:a,:c)
 
  m(:b,:a)
 
  m(:c,:a)
 
end
 
​
 
def swap()
 
  da = $towers[:a].last.to_i
 
  db = $towers[:b].last.to_i
 
  dc = $towers[:c].last.to_i
 
​
 
  ts = [da, db, dc]
 
​
 
  idx = [:a, :b, :c]
 
​
 
  ts.each_with_index do |d, i|
 
    next if d == 0 || d == 1
 
​
 
    ts.each_with_index do |dd, ii|
 
      next if dd == d
 
​
 
      if dd == 0 || d < dd
 
        return [idx[i], idx[ii]]
 
      end
 
    end
 
  end
 
end
 
​
 
​
 
def done?()
 
  $towers[:a].last == nil && $towers[:b].last == nil
 
end
 
​
 
def solve
 
  while true
 
    move_right
 
    break if done?()
 
    m(*swap())
 
    move_left
 
    m(*swap())
 
  end
 
end
 
​
 
stat()
 
solve()
 
stat()