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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**  * ***  *  *   **      ** (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