数据结构实验练习

代码说明：

数据结构实验练习--计时器，通过定义数组operand存放每个操作数，定义数组operate建立操作符集合，输入表达式得出结果。-Experimental data on the structure of practice- the timer, the array operand stored by defining the number of each operation, the definition of the array operate operator set up a collection, enter the expression results.