1 #include 
     
       2 #include 
      
        3 #include 
       
         4  5 using namespace std; 6  7 //获取符号的优先级 8 int getPriority(char c) 9 {10     int priority = -1;11     switch (c) {12     case '+':13         priority = 1;14         break;15     case '-':16         priority = 1;17         break;18     case '*':19         priority = 2;20         break;21     case '/':22         priority = 2;23         break;24     case '(':25         priority = 3;26         break;27     default:28         break;29     }30     return priority;31 }32 33 34 int main()35 {36     char c;37     stack
        
          s;38     cin >> c;39     while (c != '#')40     {41         while (isdigit(c))42         {43             cout << c;44             cin >> c;45             if(!isdigit(c) && c != '#')46                 cout << ' ';47 48         }49         if (c == ')')50         {51             //1.弹出元素并输出直到'('52             while (s.top() != '(')53             {54                 cout << s.top() << ' ';55                 s.pop();56             }57             //2.将"("也出栈58             s.pop();59         }60         else61         {62             // 下面是普通操作符的情况63             // 1.弹出栈元素直到发现优先级更低的元素64             while (!s.empty() && getPriority(c) <= getPriority(s.top()) && s.top() != '(')65             {66                 cout << s.top() << ' ';67                 s.pop();68             }69             //将本操作符入栈70             s.push(c);71         }72         cin >> c;73     }74     while (!s.empty())75     {76         cout << s.top() << ' '  ;77         s.pop();78     }79     cout << endl;80     return 0;81 }