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