计算用运算符后缀法表示的表达式的值。后缀表达式也称逆波兰表达式，比中缀表达式计算起来更方便简单些，中缀表达式要计算就存在着括号的匹配问题，所以在计算表达式值时一般都是先转换成后缀表达式，再用后缀法计算表达式的值。如：表达式(a+b*c)/d-e用后缀法表示应为abc*+d/e-。只考虑四则算术运算，且假设输入的操作数均为1位十进制数（0—9），并且输入的后缀形式表达式不含语法错误-calculated Operators suffix France said the value of the expression. Suffix expression also called inverse Poland expression, which is made up of formulas can be more convenient for some simple, ordinary expression to calculate the brackets on the existence of the matching problem, in the calculation of expression values are generally first converted into a suffix expression, reuse suffix calculated the value of the expression. Such as : The expression (a, b * c) / d-e suffix method used to be said for abc * d/e-. Consider only four arithmetic operations and the operation of input assumptions are a few decimal (0-9), and enter the suffix-free form expression syntax errors