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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  *  * **  **** * * * *  
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    *  **  *  ****  * * * ***  *  digits;
      *   *   **  ***   ** *   ***  *  ***** * 
** ** * **  * * * *    OF YOUR CODE*/
}

int main(void)
{
   int n;
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 *** ** **  *  *  * *   *  * *  ** 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)
{
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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;
*****  * **** *  **** *** *  **  ***   * *
 * *  *    *** *** *  *    *    **     * * *   *  *  * *   * 
  **** ** ** *   ** * *   * * *    **    **      ***  * ***
*  ** ** * *** * *          
     **   ***    *    ***    *  *   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