后缀式求值的方法参见我的另一篇文章 把运算符变成表达式

1 #include
     
        2 #include
      
         3 int main()  4 {
    5     int top = 0,i,k,s,num[50];  6     char str;  7     while(scanf("%c", &str),str!='#')  8     {
    9         if(str>='0'&&str<='9') 10             num[++top] = str-48; 11         else 12         {
   13             switch(str) 14             {
   15             case '+':s = (num[top-1])+(num[top]);break; 16             case '-':s = (num[top-1])-(num[top]);break; 17             case '*':s = (num[top-1])*(num[top]);break; 18             case '/':s = (num[top-1])/(num[top]);break; 19             } 20             top--; 21             num[top] = s; 22         } 23     } 24     printf("%d\n",num[top]); 25     return 0 ; 26 }