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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  ***   * *** ** * * **  *  * * *    ***   *  *****     ** 
 ** * **   * *     * *   *** 
   **** * **  **** * *** *    * (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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*  *****         *  *
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* *  * *    * * *  * * * ** 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