文曲星猜数游戏的一个简单实现

最近比较希望能做一些敏捷开发的实践，昨晚向Nick Wang请教了一下，结合自己的体会，感觉应当从单元测试开始入手，逐步了解XP的相关内容。Nick刚刚出了个小题目，感觉这是学习TDD的一个好机会。

今天看到麒麟.NET的一个非TDD实现，一时手痒也尝试了一下。由于我没有玩过那个游戏，写完后才发现有问题，就偷懒把麒麟.NET生成随机数的方法给“借”了过来。

namespace GuessGame
{
    public class GuessGame
    {
        public static readonly int NUMBER_COUNT = 4;
        
        private int[] answers = null;
        private int rightNumberCount;
        private int wrongNumberCount;
        private int wrongPositionCount;

        public GuessGame()
        {
            Init();

            GenerateDistinctRandomNumbers();
        }

        private void Init()
        {
            rightNumberCount = 0;
            wrongNumberCount = 0;
            wrongPositionCount = 0;
        }

        private void Reset()
        {
            Init();
        }

        private void GenerateDistinctRandomNumbers()
        {
            answers = new int[NUMBER_COUNT];

            Random random = new Random();
            bool allowZero = true;
            for (int i = 0; i < NUMBER_COUNT; i++)
            {
                int n = random.Next(10);
                if (n == 0 && allowZero)
                {
                    answers[i] = n;
                    allowZero = false;
                }
                else
                {
                    while (answers.Contains(n))
                    {
                        n = random.Next(10);
                    }
                    answers[i] = n;
                }
            }
        }

        public bool IsRight
        {
            get
            {
                return (rightNumberCount == NUMBER_COUNT);
            }
        }

        public string Result
        {
            get
            {
                return string.Format("{0}A{1}B", rightNumberCount, wrongPositionCount);
            }
        }

        public void Calculate(int[] inputs)
        {
            if (inputs == null || inputs.Length != NUMBER_COUNT)
            {
                throw new Exception("Invalid inputs.");
            }

            Reset();

            for (int i = 0; i < NUMBER_COUNT; i++)
            {
                int index = Array.IndexOf(answers, inputs[i]);
                if (index < 0)
                {
                    wrongNumberCount++;
                }
                else if (index != i)
                {
                    wrongPositionCount++;
                }
                else
                {
                    rightNumberCount++;
                }
            }
        }
    }

    class Program
    {
        private static readonly int GUESS_TIME = 6;

        static void Main(string[] args)
        {
            PlayGuessGame();

            Console.ReadLine();
        }

        private static void PlayGuessGame()
        {
            int[] inputs = null;
            GuessGame game = new GuessGame();

            int i = 1;
            while (i <= GUESS_TIME)
            {
                inputs = GetInput();
                game.Calculate(inputs);
                Console.WriteLine(game.Result);

                if (game.IsRight)
                {
                    Console.WriteLine("Congratulations!");
                    break;
                }

                i++;
            }

            if (!game.IsRight)
            {
                Console.WriteLine("i think you are not very clever");
            }
        }

        private static int[] GetInput()
        {
            int numberCount = GuessGame.NUMBER_COUNT;
            int[] inputs = new int[numberCount];

            Console.WriteLine("Input {0} numbers: ", numberCount);
            for (int i = 0; i < numberCount; i++)
            {
                Console.Write("  number {0}: ", i + 1);
                inputs[i] = Convert.ToInt32(Console.ReadLine());
            }

            return inputs;
        }
    }
}

完成这些代码的过程采用了我在编写自文档化的代码介绍的方法，即从伪代码开始，期望写出比较具有可读性的代码。发现写这样的小程序还是不错的:)