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