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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*  *  **  ****     ***  * * **  ***  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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 * ***  **   **** * *    * YOUR CODE HERE*/

         *    ****  ** *  ****  *
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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)
{
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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 4

Hidden content!
#include <stdio.h>
int num_digits(int n)
{
*    *  **  *** * *******   * * *   i;
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 ** **  *  ***  ** **  ***   * ** *  ***** ** * **   * ** *
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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 5

Hidden content!
#include        *  * ** 
int num_digits(int n)
{
 *  ****** *   **  *   i;
**  ** **   * * *** *** * *  * * = 0;n!=0;i++)
*    *******  **** *    
      *  ***   * * * **** *  **  **        * * ** *  = n / 10;
*******  ** * * * * * *   ** 
 ** *   ***  * **   *  ** **   i;
}

int main(void)
{
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      *** ** ** ****   
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*      **  *** ***
  * ** *  * ** ***  * **  * 0;
}

Comments

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