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++;}
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*   * ***** ** ** **       * ** 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