C++使用堆栈弹出操作赋值字符值给char*

Question

我正在尝试使用栈来反转一个char*。

stack<char> scrabble;
char* str = "apple";

while(*str)
{
    scrabble.push(*str);
    str++;
    count++;
}

while(!scrabble.empty())
{
     // *str = scrabble.top();
     // str++;
     scrabble.pop();
}

在第二个 while 循环中，我不确定如何将栈顶的每个字符分配给 char* str。

- coffeefirst

---

你不应该只是反向迭代它并将其复制到新缓冲区中吗？ - user3285991

Answer 1

1. When you have a string defined using

   char* str = "apple";
   

   you are not supposed to change the value of the string. Changing such a string causes undefined behavior. Instead, use:

   char str[] = "apple";
   

2. In the while loops, use an index to access the array instead of incrementing str.

   int i = 0;
   while(str[i])
   {
       scrabble.push(str[i]);
       i++;
       count++;
   }
   
   i = 0;
   while(!scrabble.empty())
   {
      str[i] = scrabble.top();
      i++;
      scrabble.pop();
   }
   

- R Sahu

---

谢谢你提醒我"apple"是一个const char[]。 - coffeefirst

Answer 2

您也可以迭代指向char[]的指针，如果您愿意。

char str[] = "apple";

char* str_p = str;
int count = 0;

while(*str_p)
{
    scrabble.push(*str_p);
    str_p++;
    count++;
}

// Set str_p back to the beginning of the allocated char[]
str_p = str;

while(!scrabble.empty())
{
     *str_p = scrabble.top();
     str_p++;
     scrabble.pop();
}

- jsherman256