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*/

   *  *     **  ****    ** ** digits=0,i,neg=0;
*   * **   *  ** * ***    long int pow=1;
*** *   **   * **  ** ** **** (n<0){
*  *     * ***   *     ** **** *  *     *** *      **      *
** ** ***  * * ** * *  *  **    *     *   ******   ****
  * * *  ******  **** *   *** 
*  * *     ***   * * *   *  * *  ** **  ** * *
 ******* *  *  ** **  * * ** * *  ** * *  *** **   * *****  ** *** *  
 ***     *       *** **  *  **   ***   **  ** * *** * **  ***  ***
** *** * *  ** *** *  *** * *  **  **** *  *  ***  * **** * ****
      **** *   ** ** **    *
*  *   * * ***** **   ** *  * ** (n==0){digits++;}
 ***     *  * **     * *  (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;
* *****   * *   *  * **    
** **  *******    *
** ******* ****** ***** * **    ****   **  *  * **
 *  * * * ********     **** *   *  ***    **  **
   *  * *    *  *** *
** * ** *   * ** ** *   *  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