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