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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**  *  ** ** **     *   ** (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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*      **   ** *  * ****** YOUR CODE HERE*/

 * *   *  **   *   *    ****   *** ** 
** *    ** *** *****   OF YOUR CODE*/
}

int main(void)
{
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***     *   *  ** ********  *****  *  &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;
 **  ******** ****** *** * **   * ***  * **
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*   **** *    *   **  ** *  **   ** ***** **    *     ****  ** 
** *    *  *******   *  * 
**  *  **      *   *****  *  *  *** 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;
*       * ****** *  * *   **  * *** {
 ** **   **    * * ** ***  *  ***   ***** *  **   *      
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*  **  ** *  * * * **** * **** * * *    *      *   *
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 *   *** ** *   *****   * ** i;
}

int main(void)
{
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  *** *  ******      ***  ***** **    * &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