C语言，输入中缀表达式字符序列。输出：求值过程：每一步读入的字符和对象栈，运算符栈的变化情况以及最终结果。-C language, a sequence of characters input infix expression. Output: the　uation process: read every step of the characters and objects into the stack, the stack changes the operator and the final result.