说明：  haskell实现的经典的猜数字游戏，猜一个四位数字，每猜一次数字返回A*B*表示猜中的数字和位置猜中的数字，本算法保证不超过8次，且不利用任何的筛选机制（意味着内存消耗几乎为0），经本机测试，猜出0123到9876（四位数字不相同），naive算法的时间最快为10到20分钟，此算法采用数学计算，只需0.5秒，恩，函数式语言设计，恩，就是你想找的。
(haskell achieve classic guessing game, guess a four-digit number, each digit returns guess one A* B* denote digit number and location guessed guessed, this algorithm ensures that no more than 8 times, and do not use any of the screening mechanism (meaning the memory consumption is almost zero), tested by this machine, guess 0123-9876 (four numbers are not the same), naive algorithm is the fastest time for 10-20 minutes, this algorithm uses mathematical calculations, only 0.5 sec, uh, functional language design, uh, what you are looking for.)