分段错误.是因为指针不好吗?

为什么会出现此分段错误(核心转储(？我最初被告知这是因为我的指针 p_p_tictactoe = new char*[cols]，但我被告知的不正确。每组代码的用途在整个代码中都有注释。代码正在运行，但我得到这个结果。我知道for循环必须是主要问题。

Please enter a number of rows: 4
Please enter number of columns: 3
Enter a single character for position( << i << ): a  
Enter a single character for position( << j << ): b  
Segmentation fault (core dumped)

 #include <iostream>
        using namespace std;
        int main()
        {
           // TODO:  Below each Bp_tictactoe` of type pointer-to-a-pointer-to-a-char
       char **p_p_tictactoe;

       // 2. Prompt your user to enter a number of rows, then a number of columns.
       //    store their answers in the variables `rows` and `cols`.
       char rows;
       char cols;
       cout << "Please enter a number of rows: ";
       cin >> rows;
       cout << "Please enter number of columns: ";
       cin >> cols;
       // 3. Allocate a 1-dimensional array of pointers-to-chars (length == `rows`)
       //    and store its address in `p_p_tictactoe`
       p_p_tictactoe = new char*[rows];
       // 4. Use a for-loop to allocate a dynamic array of chars (length == `cols`)
       //    for i from 0 to rows - 1 and store its address in `p_p_tictactoe[i]`.
       for (int i = 0; i < rows - 1; i++)
       {
         p_p_tictactoe = new char*[cols];
       }
       // 5. Use a for-loop to prompt the user to enter a char for each position in
       //    (" << i << ", " << j << "): "
       //    As you read each char, store it in the array.
       // 6. Use a nested for-loop to print the array, one row per line.  The chars
       //    for each row should be space-separated.  For example, if the array is
       //    2 x 3 and stores the values A, B, C, X, !, &, the output should look
       //    like:
       //       A B C
       //       X ! &

       char new_input1;
       char new_input2;
       for (int i = 0; i < rows; i++)
       {
          for (int j = 0; j < cols; j++)
          {
             cout << "Enter a single character for position( << i << ): ";
             cin >> new_input1;
             cout << "Enter a single character for position( << j << ): ";
             cin >> new_input2;
             *p_p_tictactoe[i] = new_input1;
             *p_p_tictactoe[j] = new_input2;
             cout << *p_p_tictactoe[i] <<endl;
          }  
       }
       // *** Prevent memory leaks by deallocating dynamic memory when you are done
       // using it. ***
       // 7. Use a for-loop to delete each row of the dynamic array.                

       // 8. Delete the pointer-to-a-pointer to release the array of row pointers,
       //    and set its value to NULL to avoid accessing invalid memory.
for (int i = 0; i < 3; i++)
{
delete[] p_p_tictactoe[i];
delete[] p_p_tictactoe;
}
cout << "Bye!" << endl;
return 0;
    }