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