12-07 Exercise 2: Function num_digits

Question

Write a function num_digits(n) that returns the number of digits in n ( a positive integer). Hint: to determine the number of digits in a number n, divide it by 10 repeatedly. when n reaches 0, the number of divisions indicates how many digits n originally had.

寫一個num_digits(n)函數 計算n有幾位數

#include <stdio.h>
int num_digits(int n)
{
   /*INSERT YOUR CODE HERE*/

   /*在這裡寫你的程式*/
   /*END OF YOUR CODE*/
}

int main(void)
{
   int n;
   scanf("%d", &n);
   printf("%d has %d digit(s)",n,num_digits(n));
   return 0;
}

Please complete this program by only insert your code between those tags:

   /*INSERT YOUR CODE HERE*/ 
   /*END OF YOUR CODE*/

Example input

12347

Example output

12347 has 5 digit(s)

Remember: You may correct the cases, but your code always be revised!

Answer 1

Hidden content!
#include <stdio.h>
int num_digits(int n)
{
 * *   ***             YOUR CODE HERE*/

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  **     ** ** *  * **  long int pow=1;
   * *   *     *  ****** *  * (n<0){
* * * * *  **    ****** *****   * ***  **** * ***   ***
****  * ***     ** **  ***  *    *   * * * * ** ** * *  * *  
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*  * *  *  * **  **  *   * 
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* * * * *  ** *** ** * **  ****  (neg==1){n=n*-1;}
** * *  * **     *****       **    digits;
  *** ** *       * *  *  *  * **    ** *
 **  * * ** *    *  **  OF YOUR CODE*/
}

int main(void)
{
   int n;
*      **   * ** *   ** **  *  * ** &n);
**  *** ****** * *  *  ** ** * * *  *  has %d * ***** ** *** *   *  
** * * *  *  ***** *  *    0;
}

Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output

Answer 2

Hidden content!
#include <stdio.h>
int num_digits(int n)
{
    **  *  **   **  * *** i=0;
       ****   *   ***   **** *
   *  *   * * ***
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 *  **  ** *   *   **** i;
  ***   *****     ***     YOUR CODE HERE*/

   *** *  *********  *    ** *  *  **
****   *  **  ** ***  OF YOUR CODE*/
}

int main(void)
{
 **** *****  **   * n;
  * * *   **   ***  * *** * * ** ** *** *  * * &n);
   * *** ** **      *** * *  *     *** * has %d   ***        *  *   *
***      *  *  * ****** 0;
}

Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output

Answer 3

Hidden content!
#include <stdio.h>
int num_digits(int n)
{
***  *** * ***   **** *    *  * counter=1;
   * ** ***  * ******* *   *     **
  *** **   ****  * ****   ** *  ****** **  *** * * *
** **   *** *  *****   *  ** *****     * **    ** * ****  **
  * * * *  **  *** **   * *
      *     * ** * **   *  **  *   * counter;
}

int main(void)
{
* **  *  ** **  *  **   ** n;
* *****  **** **     ****** ** *****  *    &n);
*    * * *** *  *** *   *    * ** has %d  *    *   **  ****  * *  * 
 *   ** *  ***  ** ***   0;
}

Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output

Answer 4

Hidden content!
#include <stdio.h>
int num_digits(int n)
{
* ** *** * **    **** * * i;
       * * **    *  * *      ***** **  {
***   *  ***  *** * ** *** *  ** **  ** **   *    *  * *  
  ***  *  *   *** * * * *****  ***       ***  * ** **** **** break;
* ***  ** *** *   ** * *  *** *  ** * ** ***** ** *** 
 **  *** *    ***   *      *
 **** *     * **   * **  **  *    i;
}

int main(void)
{
 * * **** ***** ** *** n;
*  * * *** **  ** *    * **   ***   ** * &n);
*     ** *   * * *  * ****   **  has %d   *    **   *  ***   * *
****  *  **** * * ** 0;
}

Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output

Answer 5

Hidden content!
#include  ***** *   * *
int num_digits(int n)
{
    * * *   * *     *  * i;
*      **   **     * **  * * = 0;n!=0;i++)
** *** **** *    * * ** ***  
 **   ****** * **      *** *  * * * * *** **  *** ** = n / 10;
 **   ***     *  *  *   ** **  
*  * * * ********  * **  i;
}

int main(void)
{
***    *** *  **  *       n;
 *   * * **   *       *   ***  **    * *  &n);
 * *** * **  **** * 
   * * ** *  *** *   * **   *  * has %d  *   * * * **  ** **  **
*  *  * *   ***      *
* * *    *  * *   * *****  0;
}

Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output