首先简介下题目:
输入:一个不超过12位的十进制正整数
输出:打印此数字的十进制计算器表示
例:
输入:145
输出:
__ ||__||__ | | __|看到这个题目,也没多想,反正就是把这些数字打出来而已,那就一行一行打呗 于是在纸上画了几个计算器表示形式的数字: 规律是很明显的,每个数字都由3行4列组成,每一行只有固定的几种样式,比如说8的第一行是" __ ",第二行是"|__|",第三行是"|__|" 于是就有了思路:只要一位一位的读取这个数字,然后按照上中下的顺序依次打印其计算器表示的三行就行了。 由于每个数字的每一行的样式都是固定的,很容易将这些样式抽取出来,经过观察,我找出了其所有的样式,于是就有了如下的代码:
class LCDPrinter { // all the paradigms in the LCD representation private static readonly string S0 = " "; private static readonly string S1 = " __ "; private static readonly string S2 = " |"; private static readonly string S3 = "| "; private static readonly string S4 = " __|"; private static readonly string S5 = "|__ "; private static readonly string S6 = "|__|"; private static readonly string S7 = "| |"; public void PrintNum(int value) { //TODO: print the number layer by layer } }接下来的问题就是依次获取一个数的每一位,通过一个递归,很容易实现这个功能:
public void PrintNum(int value) { if (value != 0) { PrintNum(value / 10, layer); Console.Write(value % 10); } }测试这个方法之后,接下来的工作就是一行一行的打印数值了,按照之前的思路,我把每个数字分为上中下三层,于是可以这么写:
public void PrintNum(int value) { PrintTopBody(value); Console.WriteLine(); PrintMiddleBody(value); Console.WriteLine(); PrintBottomBody(value); Console.WriteLine(); }然后逐个实现每个方法,为了确保这个思路是正确的,先不用考虑所有的数字,只考虑数字1这个情况
private void PrintTopBody(int value) { if (value != 0) { PrintTopBody(value / 10); int num = value % 10; switch (num) { case 1: Console.Write(S0); break; default: throw new ArgumentOutOfRangeException(); } } } private void PrintMiddleBody(int value) { if (value != 0) { PrintMiddleBody(value / 10); int num = value % 10; switch (num) { case 1: Console.Write(S2); break; default: throw new ArgumentOutOfRangeException(); } } } private void PrintBottomBody(int value) { if (value != 0) { PrintBottomBody(value / 10); int num = value % 10; switch (num) { case 1: Console.Write(S2); break; default: throw new ArgumentOutOfRangeException(); } } }然后以1,11,1111作为输入进行测试,发现结果是正确的。 接下来就可以完善这三个方法了,经过一段时间的编码和测试,我完成了这道题目。其功能代码如下
class LCDPriter { private static readonly string S0 = " "; private static readonly string S1 = " __ "; private static readonly string S2 = " |"; private static readonly string S3 = "| "; private static readonly string S4 = " __|"; private static readonly string S5 = "|__ "; private static readonly string S6 = "|__|"; private static readonly string S7 = "| |"; public void PrintNum(int value) { PrintTopBody(value); Console.WriteLine(); PrintMiddleBody(value); Console.WriteLine(); PrintBottomBody(value); Console.WriteLine(); } private void PrintTopBody(int value) { if (value != 0) { PrintTopBody(value / 10); int num = value % 10; switch (num) { case 0: Console.Write(S1); break; case 1: Console.Write(S0); break; case 2: Console.Write(S1); break; case 3: Console.Write(S1); break; case 4: Console.Write(S0); break; case 5: Console.Write(S1); break; case 6: Console.Write(S1); break; case 7: Console.Write(S1); break; case 8: Console.Write(S1); break; case 9: Console.Write(S1); break; default: throw new ArgumentOutOfRangeException(); } } } private void PrintMiddleBody(int value) { if (value != 0) { PrintMiddleBody(value / 10); int num = value % 10; switch (num) { case 0: Console.Write(S7); break; case 1: Console.Write(S2); break; case 2: Console.Write(S4); break; case 3: Console.Write(S4); break; case 4: Console.Write(S6); break; case 5: Console.Write(S5); break; case 6: Console.Write(S5); break; case 7: Console.Write(S2); break; case 8: Console.Write(S6); break; case 9: Console.Write(S6); break; default: throw new ArgumentOutOfRangeException(); } } } private void PrintBottomBody(int value) { if (value != 0) { PrintBottomBody(value / 10); int num = value % 10; switch (num) { case 0: Console.Write(S6); break; case 1: Console.Write(S2); break; case 2: Console.Write(S5); break; case 3: Console.Write(S4); break; case 4: Console.Write(S2); break; case 5: Console.Write(S4); break; case 6: Console.Write(S6); break; case 7: Console.Write(S2); break; case 8: Console.Write(S6); break; case 9: Console.Write(S4); break; default: throw new ArgumentOutOfRangeException(); } } } }虽然这段代码可以工作,但是怎么看怎么别扭,不知所以然的S0到S7这8个全局字符串(本身就不好命名),逻辑极其类似的PrintTopBody,PrintMiddleBody,PrintBottomBody这三个方法,使得逻辑很简单的一个程序却很难看懂。