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)
{
 *  * * * **    **       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