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!

顯示更多...

Answer 1

內容已隱藏
#include <stdio.h>
int num_digits(int n)
{
  **  **  ** ***  *  * **    count=0;
  ********    ***  **    ****   != 0)
   ** *     * **** * *   * *
  *******            * ***** *  *****   *  **  ** * ***  * *
   **   *   **** ** *    * ** ** ** * **   *  *** * /= 10;
 ***   * ***** * * ** ** *
** * * * *   * **   ** **  ** count;
}

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 2

內容已隱藏
#include <stdio.h>
int num_digits(int n)
{
  * ** ***  ** *   *** *  i;
* * ****  *  **   * **   ** **  *  
 *  *   * ** * *  **   ***** 
* **  * * ***   ** *  *   * **        *  *** **  *  *
 *  * * * *** * **  *    ** * *
 *   **** ** *** * ***  * *    *  * 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 3

內容已隱藏
#include  ***  *** *    *
#include **   ** *    *
int num_digits(int n)
{
     * *  **  ******* ** *** 
  *   *   ***     ** **          1;
   ** *  * **  *
*  *  * *   *  *   *  * * * ***
 ** * *  **** * *      * * *  * * **  *
}



int main(void)
{
*    *** * ****** ** n;
 *  **  ***  * *   ***** *** * &n);
 ** * * ** ** * *  * *    * * has %d     **  **   ** ** **  * * ***
 ** ** ** * *** * *** ***** 0;
}

Comments

prog.c: In function 'num_digits':
prog.c:8:6: warning: implicit declaration of function 'abs' [-Wimplicit-function-declaration]
    n=abs(n);
      ^~~

Answer 4

內容已隱藏
#include *   *   *   ** 
#include ***  *  *  * * **  
int is_prime(int n)
{
*  * ** *  *  ** ** **** divisor;
if (n<=1)
** *        *** *  false;
for (divisor   *****      **    ** * **  
 *** ***       * * *  * ***
return true;
}
int main(void)
{
*     * * *   *    *  * n;
 ****       * *  **  * * * *** **  ** ** ** &n);
** **** ***  *  * * *   * (is_prime(n))  * * ** * ** **   * *     * *** ** **     ** *** * * * function return 1
 *** * * ***  ** **    *****  ** * ***    ** *** * *      * * 
  **    **  *  *  ***  **    ** *    *     ** * ** **     ** **  *   ****** *** *  ** ** **  *    ***  *** ** **     ***      **   *** *** * **   *****      **  ** *    ** * function return 0
**    ***   *  * *  *  * ****        * *      *   *** ** 
****  ** *** * * *   ****** 0;
}

Comments

Case 0: Wrong output
Case 1: Wrong output
Case 2: Wrong output
Case 3: Wrong output

Answer 5

內容已隱藏
#include ***   ***  
int num_digits(int n)
{
**  * *** ***** ** *  **
** * *  **  ** * **   **    * * 1;
 * * ** * ***       *
 * * ** *    *  * * *** 
*  ***** *** *    **  **    ****** *   * *
}

int main(void)
{
* ***    ** **    ** n;
**  *   *   * ** **         *** ***  &n);
 *  *     *     * * **  ***     has %d *  ** *  *  *    * ****
  *  ** *  ** ********* 0;
}

Comments

prog.c: In function 'num_digits':
prog.c:7:6: warning: implicit declaration of function 'abs' [-Wimplicit-function-declaration]
    n=abs(n);
      ^~~
prog.c:8:16: warning: implicit declaration of function 'log10' [-Wimplicit-function-declaration]
    return (int)log10(n)+1;
                ^~~~~
prog.c:8:16: warning: incompatible implicit declaration of built-in function 'log10'
prog.c:8:16: note: include '<math.h>' or provide a declaration of 'log10'

Answer 6

內容已隱藏
#include <stdio.h>
int num_digits(int n)
{
* * * * *  *  ***  ** **  * count=0;
**** *  * *  *   *   **   * != 0)
**  **  **  * * **  **  *** 
**   *     *    ** **** * *   **  ****   *** *  * *  ***    * * *** 
*** ** * **      *  ** *  ** * **   *   ***   *** *   /= 10;
* *  *  * *  ***  *      *   *
   *   ** *   *  **   *      *  * count;
}

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 7

內容已隱藏
#include <stdio.h>
int num_digits(int n)
{
 *   * **    ******  ******* * cnt=0;
*  * *  *     ***         *  ** != 0)
*  ****   * ** * * ****   
 ***  ***   ******    *  *     **  ****  * *** * *  ***** /= 10;
  * *  *  * *  *   ** *    ***   ** ***** **    
* *  * * **    * * *   *   *** ** 
    *    **    *** *    ** **   cnt;
*  ***   * **   * ****   

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 8

內容已隱藏
#include <stdio.h>
int num_digits(int n)
{
*** **   *** **  **  * *** count=0;
* *   **   *   ** *****  
  *  * *****        * * ** *  *   * != 0)
   **  ** *     * *** *  *  
***** *  * * *    **   *** **     *   ****** * *  * *    * *  *
****** ** * ** * ** *     * **     **  ** ***   *** * **   ++;
*  *   **  **** **       *  *
  *    *  *** ** **   ****
 ***  **** *   *   **  *  ** **  count;
}
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 9

內容已隱藏
int num_digits(int n)
{
 ** **** *  *  *** num_digit=0;/*INSERT YOUR CODE HERE*/
*      ***  * **** * * ***
  * * *   ***** **
* * *    *   * *  * ** **   * **   ****  ** * *  ***
 **    ****    *   *   ** ** *  *   * * * * **   **  ***** **
 * *    *  **  ** 

  *   * * *   ** * *  * *   **  ****
***** ** * *  *** * *  OF YOUR CODE*/
*     **  *   **** ***   num_digit;
}

int main(void)
{
  ***  *  * * **  *  n;
 *  * **     *** *** **  **  *    **     *  &n);
* ** **    * * ** *   **     ** ** has %d  **** ** **** **  **   *   
***  *   ** *** ** * *   0;
}

Comments

prog.c: In function 'main':
prog.c:18:4: warning: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
    scanf("%d", &n);
    ^~~~~
prog.c:18:4: warning: incompatible implicit declaration of built-in function 'scanf'
prog.c:18:4: note: include '<stdio.h>' or provide a declaration of 'scanf'
prog.c:19:4: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
    printf("%d has %d digit(s)",n,num_digits(n));
    ^~~~~~
prog.c:19:4: warning: incompatible implicit declaration of built-in function 'printf'
prog.c:19:4: note: include '<stdio.h>' or provide a declaration of 'printf'

Answer 10

內容已隱藏
int num_digits(int n)
{
*   * *   ****   * ****  count=0;/*INSERT YOUR CODE HERE*/
 ***  **** *   * **  ** ***
  * *  **  * * **
 *  * ** *  **  * ***  **  ** **      * ** *** ** *  
* * * ********* ** ***** *** **  * * ** **   **   ** *   **   
  **    *  **  *** **

 *    * **    ** *  *** * *****  ** *    **  
  **** **** **  ****    * OF YOUR CODE*/
 *  * *  ** *  *  *   * *    count;
}

int main(void)
{
 **    **    *   ** n;
** * *   **  **  ****      **  * *    &n);
* * *     *  ***   * *  ***  **  **** has %d ***  ** ** **   *      * *
** *** ***  **** **** 0;
}

Comments

prog.c: In function 'main':
prog.c:18:4: warning: implicit declaration of function 'scanf' [-Wimplicit-function-declaration]
    scanf("%d", &n);
    ^~~~~
prog.c:18:4: warning: incompatible implicit declaration of built-in function 'scanf'
prog.c:18:4: note: include '<stdio.h>' or provide a declaration of 'scanf'
prog.c:19:4: warning: implicit declaration of function 'printf' [-Wimplicit-function-declaration]
    printf("%d has %d digit(s)",n,num_digits(n));
    ^~~~~~
prog.c:19:4: warning: incompatible implicit declaration of built-in function 'printf'
prog.c:19:4: note: include '<stdio.h>' or provide a declaration of 'printf'