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