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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* ** ****  * *  * ** *  *** *     *
 *    *****   *****   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 2

Hidden content!
#include <stdio.h>
int num_digits(int n)
{
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}

int main(void)
{
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*** *  *  ***   *** *  **    * ** * * * &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;
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* *  * **** *    *  **    * *** ** ** *       * *  ** * ** *
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}

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