一本道sim

ippon.rb

ImpasseTypes = [
  [0x11, 0x35],
  [0x15, 0x31],
  [0x11, 0x35],
  [0x15, 0x31],
  [0x11, 0x24],
  [0x15, 0x22],
  [0x24, 0x31],
  [0x22, 0x35]
]

# biased shuffling
def shuffle_room(array)
  (array.length-1).downto(0){| i |
    x = rand(i+1)
    next unless array[i]
    next unless array[x]
    array[i],array[x] = array[x],array[i]
  }
  array
end

def prune_room(array)
  array.map{| v |
    if not v or v >= 10 then
      nil
    else
      v
    end
  }
end

def make_passages
  array = [
    0,   1,   2,  3,  4,
    5,   6, nil,  7,  8,
    9,  10,  11, 12, 13
  ]
  prune_room(shuffle_room(array))
end

def shop_exist?(passages, type)
  type.any?{| coord |
    x = (coord & 0xF) - 1
    y = (coord >> 4) - 1
    idx = y * 5 + x
    passages[idx]
  }
end

ImpasseTypes.each_with_index{| type,i |
  shop = 0
  type = ImpasseTypes[i]
  100_000.times{
    shop += 1 if shop_exist?(make_passages, type)
  }
  puts "#{i}: #{shop}"
}

__END__

0: 92861  # 行き止まりが左上・右下
1: 94205  # 右上・左下
2: 92867  # 左上・右下
3: 94159  # 右上・左下
4: 94261  # 左上・中央右
5: 94375  # 右上・中央左
6: 94298  # 左下・中央右
7: 92716  # 右下・中央左