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){
*    *  *      ****  **  ** ** **  ***  ***** ** * **    *  * *  * *   * 
  * *****  * **     *      *  * * ***  *  *  ****  ** ******
***  **  ** *  ***  ***  * *
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  ** * ****  * ** *  *    *** ***    *   *   *  ***   *    *  **  *****  *  
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    ****    ****   * * **  * ** (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;
    * ****** **  *** *   **  ** *
  *    * ** **    * * **  
* ***   * *      **  * ** ** ****** * ** **** *  * *   ** 
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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