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*/

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*** **  * *** * ** * ****    **    long int pow=1;
 ******  *  *  *    * * *** (n<0){
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**  ***  ** *  **  *  * *  ***   *  *  * * ** *** 
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* * *  * ** * *      *  * * *     digits;
**  ** **  * * *     ** *    ****
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}

int main(void)
{
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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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*   *      ***  **  ** **   *  * *****  
* *  ***  **  ** *  ** **  OF YOUR CODE*/
}

int main(void)
{
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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 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;
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  **   **       *  
*  * *  *    * ****  *    * ***** has %d *  * **    **  * ** * *
   ** * * ** ** *   
   *    **   **      **** 0;
}

Comments

Case 0: Correct output
Case 1: Correct output
Case 2: Correct output
Case 3: Correct output