该程序为从原四则表达式求得后缀表达式，使用栈的数据结构，使用当前运算符与栈顶运算符进行比较，优先级高则入栈，之后出栈所有优先级比当前高的运算符，输入为 # 结束时,把栈中的运算符全部弹出-The program from the original four suffix expressions obtained expressions, the use of stack data structure, using the current Top-operator with the operator to compare the high-priority入栈, followed by a stack of all high-priority than the current computing Fu, enter# the end of the stack of all the pop-up operator