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