用静态栈数据结构实现表达式求值[9]

//判断优先级的函数

char priority(char y,char x){

        char priority='<';

        switch(x){

            case '+':

            case '-':if(y=='(' || y=='#')priority='>';break;

            case '*':

            case '/':if(y=='(' || y=='#'|| y=='+' || y=='-')priority='>';break;

            case '(':priority='>';break;

            case ')':if(y=='(')priority='=';break;

            case '#':if(y=='#')priority='=';break;