程序开始运行，要求用户首先输入两个大数。

然后进行菜单选择，进行相应的大数运算。



分析说明：由于大数的范围太大，不能直接定义为int或者float等，

所以我们的想法就是定义成字符串类型，

输入的数字一位一位地存入字符数组里面。

然后在运算的时候也是一位一位地运算。

这个过程就得从最基本的数学运算法则做起，不乏多种判断。

涉及到数组和指针的应用。最难的就是判断情

况还有应用数组和指针过程中出现的多种未可预知的错误，

还得通过逐步调试慢慢找出。我们先从加减法做起，然

后在这两个基础上做出乘除法还有高阶乘法。

比较麻烦的是减法和除法，因为涉及到位的转移及判断。

最后是main函数的设计，主要是设计成可以连续使用的，

还有就是比较友好的界面。运用到了swich函数。还有那个图形的设计。-Program started running, require the user to enter first two operation.

Then the menu option, undertake corresponding tarsus operations.



Analysis in this paper shows that: because of the large range is too big, can not directly defined as int or float,

So our idea is defined as a string literal,

The number of input a a deposit to string array inside.

And then in the operation of time also is a a ground operations.

This process will have to from the most basic mathematical algorithms, starts to there is no lack of judgment.

Involves the application of array and pointer. The most difficult judgment is feeling

Conditions and application array pointer and appeared in the process of many unforeseen predictable wrong,

Still have to go through gradually debugging slowly find out. We start from the first addition and subtraction, however

In the two after a method based on the mentalistic and high factorial method.

More trouble is subtraction and division, and because of the transf