a little logic game in fragments

overflow_game.rb

MAX_CAPACITY = 3

def show(m)
  puts "="*12,m.map{|l|' '<<l.map{|e|'*123456789'[e]}.join(' ')}.join("\n"),"="*12
end

def pop(map, x,y)
  m = map.map(&:dup)
  return m if x < 0 || y < 0 || x >= m[0].size || y >= m.size
  if m[y][x] == MAX_CAPACITY
    m[y][x] = 0
    m = blast(m,x,y,-1, 0)
    m = blast(m,x,y, 1, 0)
    m = blast(m,x,y, 0,-1)
    m = blast(m,x,y, 0, 1)
  elsif m[y][x] > 0
    m[y][x] += 1
  end
  m
end

def blast(map, x,y, dx,dy)
  m = map.map(&:dup)
  loop do
    x += dx
    y += dy
    return m if x < 0 || y < 0 || x >= m[0].size || y >= m.size
    if m[y][x] == MAX_CAPACITY
      m = pop(m,x,y)
      return m
    elsif m[y][x] > 0
      m[y][x] += 1
      return m
    end
  end
end

def finished?(m)
  !m.flatten.find{|e|e>0}
end

def element_positions(m)
  ep = [].tap{|a| m.each_with_index{|r,y| r.each_with_index{|e,x| a<<[[x,y],e] if e > 0}}}
  (rand(0..9) < 4 ? ep.shuffle : ep.sort{|a,b| b[1]<=>a[1]}).map(&:first)
end

def all_games(m, moves=[], games={})
  return games if games.any? && moves.size > games.values.first #optimization
  return games if games.size >= 250 #limit
  ep = element_positions(m)
  return games.merge!(moves => moves.size) if ep.empty?
  ep.each do |p|
    games.merge! all_games(pop(m,*p), moves+[p], games)
  end
  games
end

maps = [
  [[0,0,0,0],
   [0,3,3,0],
   [0,1,2,0],
   [0,0,0,0]],

  [[3,1,2,2],
   [2,2,2,2],
   [2,1,3,2],
   [2,2,2,2]],

  [[1,1,3,1],
   [2,3,2,3],
   [1,1,3,1],
   [1,1,2,1]],

  [[1,1,3,2],
   [1,1,2,1],
   [2,2,3,3],
   [1,2,1,2]],

  [[0,2,3,0],
   [3,0,0,3],
   [2,0,0,2],
   [2,2,3,2]],

  [[2,2,2,0],
   [2,2,1,2],
   [2,1,2,3],
   [0,2,3,0]],

  #experimental
  [[2,2,0,3],
   [2,0,0,0],
   [0,0,0,2],
   [3,0,2,2]],
]


games = all_games(maps[6])
games.sort{|a,b|b[1]<=>a[1]}.each do |g|
  puts "#{g[1]} moves: #{g[0].inspect}"
end
puts games.size
exit


maps.each do |m|
  show m
  i = 0
  begin
    x,y = gets.strip.split.map(&:to_i)
    m = pop m, x, y
    show m
    i += 1
  end until finished? m
  puts "Level cleared in #{i} moves!\n"
end