1.编写生成栈的函数，栈的元素从键盘输入

2.编写在栈中压入一个元素的函数

3.编写在栈中弹出一个元素的函数

4.编写主函数，调用以上各函数，以便能观察出各函数的屏幕输出。

-1. Preparation of the function generating the stack, the stack of elements from the keyboard 2. Preparation of pressure on the stack into an element of the function 3. Write an element in the stack pop-up function 4. Write the main function, call the above function in order to observe the function of the screen output.