第六章第三十题（游戏：双骰子赌博）(Game: craps)

**6.30（游戏：双骰子赌博）执双骰子游戏是赌场中非常流行的骰子游戏。编写程序，玩这个游戏的一个变种，如下所描述： 执两个骰子。每个骰子有六个面，分别表示值1，2，…，6。检查这两个骰子的和。如果和为2、3或12（称为掷骰子（crap））,你就输了；如果和是7或者11（称作自然(natural)）,你就赢了；但如果和是其他数字（例如：4、5、6、8、9或者10），就确定了一个点。继续掷骰子，直到掷出一个7或者掷出和刚才相同的点数。如果掷出的是7，你就输了。如果掷出的点数和你前一次掷出的点数相同，你就赢了。程序扮演一个独立的玩家。

下面是一些运行示例：
You rolled 5 + 6 = 11
You win

You rolled 1 + 2 = 3
You lose

You rolled 4 + 4 = 8
point is 8
You rolled 6 + 2 = 8
You win

You rolled 3 + 2 = 5
point is 5
You rolled 2 + 5 = 7
You lose

**6.30(Game: craps)Craps is a popular dice game played in casinos. Write a program to play a variation of the game, as follows:Roll two dice. Each die has six faces representing values 1, 2, . . ., and 6, respectively. Check the sum of the two dice. If the sum is 2, 3, or 12 (called craps), you lose; if the sum is 7 or 11 (called natural), you win; if the sum is another value (i.e., 4, 5, 6, 8, 9, or 10), a point is established. Continue to roll the dice until either a 7 or the same point value is rolled. If 7 is rolled, you lose. Otherwise, you win. Your program acts as a single player.

Here are some sample runs.
You rolled 5 + 6 = 11
You win

You rolled 1 + 2 = 3
You lose

You rolled 4 + 4 = 8
point is 8
You rolled 6 + 2 = 8
You win

You rolled 3 + 2 = 5
point is 5
You rolled 2 + 5 = 7
You lose

下面是参考答案代码:

public class CrapsQuestion30 {
	public static void main(String[] args) {
		int sumOfTwoDice,firstDie,secondDie,point;
		
		firstDie = rollDie();
		secondDie = rollDie();
		sumOfTwoDice = firstDie + secondDie;

		if(sumOfTwoDice == 2 || sumOfTwoDice == 3 || sumOfTwoDice == 12)
		{
			System.out.printf("You rolled %d + %d = %d\n",firstDie,secondDie,sumOfTwoDice);
			System.out.println("You lose");
		}
		else if(sumOfTwoDice == 7 || sumOfTwoDice == 11)
		{
			System.out.printf("You rolled %d + %d = %d\n",firstDie,secondDie,sumOfTwoDice);
			System.out.println("You win");
		}
		else
		{
			point = sumOfTwoDice;
			System.out.printf("You rolled %d + %d = %d\n",firstDie,secondDie,sumOfTwoDice);
			System.out.printf("point is %d\n", point);
			do {
				firstDie = rollDie();
				secondDie = rollDie();
				sumOfTwoDice = firstDie + secondDie;
			}while(sumOfTwoDice !=7 && sumOfTwoDice != point);
			
			System.out.printf("You rolled %d + %d = %d\n",firstDie,secondDie,sumOfTwoDice);
			if(sumOfTwoDice == point)
				System.out.println("You win");
			else if(sumOfTwoDice == 7)
				System.out.println("You lose");
		}
	}
	public static int rollDie() {
		return (int)(Math.random() * 6 + 1);
	}
}

运行效果：

注：编写程序要养成良好习惯
1.文件名要用英文，具体一点
2.注释要英文
3.变量命名要具体，不要抽象（如:a,b,c等等），形式要驼峰化
4.整体书写风格要统一（不要这里是驼峰，那里是下划线，这里的逻辑段落空三行，那里相同的逻辑段落空5行等等）
5.普通变量，方法名要小驼峰，类名要大驼峰，常量要使用全部大写加上下划线命名法
6.要学习相应的代码编辑器的一些常用快捷键，如：快速对齐等等