按照书上介绍介绍的方法，模拟编译器计算表达式的方法，就是对栈的反复操作，具体算法见数据结构书。其中对运算符优先级确定上用到令一本书的算法。-In accordance with the method described in the book presented to simulate the calculation expression compiler method is repeated on the stack operation, the specific data structure algorithms see the book. In which pairs of operator precedence is used to determine the algorithm to make a book.