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