该课程设计通过使用flex和bison编写了一个科学计算器的程序，运行时，出现dos界面，在其中输入您想要进行计算的数学表达式，并设定显示方式，就可以按照您的要求显示出计算结果。-The curriculum design through the use of flex and bison to prepare a scientific calculator program, run-time, there dos interface, in which you want to enter mathematical expressions, and set the display, you can display in accordance with your request the calculated results.