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