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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**** * ** *  ** ** ***  **** ** *  *  *  ****** **
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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