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){
   * *** * *     *** * *   * * ** *   **     **  ** *
   ** * * *   ** * ****  * * * *        *** *   *  * ** ***    **
    *         * * * **    
**  ** * ** ***   * *        ** ***  *  
*** * ***  ** *  ***   ****** ** **   * *  **            ** *    ****  *** *  
    *** * * **  * * ** *   *        *   * ***** * * **** * **    * *  
*** ** ****    **   *    * *** *  *  *   *     *      ****** ***   
*****  *   * ** ** ***   * **
***  *   * **  ** ** ** (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;
* *  **    * * ** *****  *****   **
**    **   ** *  * **
 *   * ***     ***    *** ** *   * *** ** *    *    
  *  ** *  *  * * * ** **    *  *   * *      * ** **
* **** *     * **    *
 *  ** **    ** *    **    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