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;
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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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** * * *  **   *  **** *  ** * 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