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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 * *** *****      ***  ** 
* * *   ** *   *     ****   **   (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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* *  ** **   **  ***     * 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;
  *  * **  ******** *********** *  ** * *  
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*  ** ****    ***  **  ** ****   ***       ** * * ** *  **  
*  ****** ***   ***  ** ******
* *  **  ****    *** ** **   **  * 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