10-19 Exercise 1: International Standard Book Number (ISBN)

Question

The 13-digit International Standard Book Number (ISBN) is a unique code that identifies a book commercially. The last digit is a check digit used for error detection. To calculate its value, each digit of the first twelve digits is alternately multiplied, from left to right, by 1 or 3. The products are summed up and divided by 10. The check digit is the remainder of the division subtracted from 10. If it is 10, it becomes 0. 

ISBN檢查號的計算方法: 前12個數字，奇數項 乘以 1 ， 偶數項乘以 3

For example, assume that the first twelve digits are 978960931961.  

假設號碼前12位是978960931961

(a) (9*1 + 7*3 + 8*1 + 9*3 + 6*1 + 0*3 + 9*1 + 3*3 + 1*1 + 9*3 + 6*1 + 1*3) = 126 

(b) The check digit = 10 – (126 % 10) = 10 – 6 = 4  

檢查號 = 10 - 餘數 = 10 – (126 % 10) = 10 – 6 = 4  

So the valid ISBN is: 9789609319614

Write a program that reads a 13-digit ISBN and checks the last digit to see if it is valid or not. 

寫一個輸入13位ISBN號碼 判斷最後一個數字是否檢查碼即可

#Try 1:

Input:

9789609319614

Output: 

Valid ISBN

 

#Try 2:

Input:

9781482214505

Output: 

Valid ISBN

 

#Try 3:

Input:

9780132936493

Output: 

Invalid ISBN

 

Answer 1

Hidden content!
#include <stdio.h>

int main()

{
* **** **** *** * * * * *** * ** * ** * ** *
* ** * * **** * * * ** * * * * ** * * * * ******* * * * * * ** * * * * ** *** * ** * * * ****** * * * * * *** ** **** ** *** ** * *
** ** * ** *** * *** ** * * ***** * * * * ** * * * * * *** **


****** * * ******** ** **
* ** *** * * ** ** *** * * * **** ** * * * ISBN");
* * ** * ** *** ** ** *

   else
* **** ** ***** **** ** * * * ***** **** * ** ** * ISBN");

   
* * * ***** * ** *** ** *** * ** 0;



}

Comments

prog.c: In function 'main':
prog.c:11:4: error: this 'else' clause does not guard... [-Werror=misleading-indentation]
    else
    ^~~~
prog.c:14:8: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'else'
        return 0;
        ^~~~~~
cc1: all warnings being treated as errors

Answer 2

Hidden content!
#include <stdio.h>

int main()

{
*** * * * *** ** *** ** ** ** ** ****** * *
**** ***** * * * * * ***** * * * ***** * * *** ** ** * * ** ***** * ** ***** *** * * *** *** ** *** ****** ****** ** * ** * * ** * * ** *
** ** ** * *** *** ** * ** **** *** **** * ** ** * ** ** *******


** * ** * **** ******* ** * ***
* ***** * * * * * * ** * *** * ****** ***** ** * * ISBN");
**** * *** * *

   else{
** ** * * * ** *** * *** * **** *** * *** * * * ISBN");

   }
* ** * * **** * * * * ***** *** * * ** 0;



}

Comments

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

Answer 3

Hidden content!
#include <stdio.h>

int main()

{
* ******* *** * * ** ** ** * * *** *** ** ****
*** * *** ** * *** ** * * * * * **** * *** * ** * * * * * ** * **** * ** *** * **** * ** * **** * ***** ***** ** * *** * * * ** ** ** *** ** *
* * ** * *** * * ** * ** * * ** * * ** ** *** * * ***

   if (b12==total)
** * * * ** ** *** * ** ** *** ***** *** **** * **** ISBN");

   else
* * * ** ** * *** *** ***** **** **** * * ***** * ISBN");


** ** * * * *** **** *** * *** * *** * * 0;



}

Comments

prog.c: In function 'main':
prog.c:9:4: error: this 'else' clause does not guard... [-Werror=misleading-indentation]
    else
    ^~~~
prog.c:12:8: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'else'
        return 0;
        ^~~~~~
cc1: all warnings being treated as errors

Answer 4

Hidden content!
#include <stdio.h>

int main()

{
*** * * * **** * *** * * * ****** * ** *** ** **
***** *** * ** ****** ** * * * ** ** **** * * ****** * ** * ** * ** * *** *** * * * * * * * ** ** *** * ** *** *** ** *** ***
* ** *** * ****** ** * ** **** *** ** * **** **** * **

   if (b12==total)
* * * ** * * *** *** * ** **** ***** * * ISBN");

   else
* *** * * * * * * * *** *** *** *** *** * ISBN");


* * * * * ** **** ** * * * *** * * 0;



}

Comments

prog.c: In function 'main':
prog.c:9:4: error: this 'else' clause does not guard... [-Werror=misleading-indentation]
    else
    ^~~~
prog.c:12:8: note: ...this statement, but the latter is misleadingly indented as if it is guarded by the 'else'
        return 0;
        ^~~~~~
cc1: all warnings being treated as errors

Answer 5

Hidden content!
include <stdio.h>
int main()
{
*   * * * *  *** *  ** * ** *** * ****  *   **     *****  ** ***
 * **    *     * ** * * *   *  *****  ****   *** ** ** * *     * ****  **** *   ** **** ***   * ** * * * *  *** *       ** ***   ***    **  *   ** *  **     * **   *******
* * *****   *****       ** * *     *   * *  ****  * * *        * *******   * * ** **
   if (b12==total)
*  * ***   *  *     ******  *  *****   **** * *** *** ** **    *  *   ISBN");
   else
 **  *  *  **   * ** ****   *** *  ** * *  * *** *  *** ISBN");

 *  ** *  * *******  *  *** ** * **  **** * *   **  **** 0;

}

Comments

prog.c:1:9: error: expected '=', ',', ';', 'asm' or '__attribute__' before '<' token
 include <stdio.h>
         ^

Answer 6

Hidden content!
#include   *** ****  *   
int main()
{
****   **  **  **    ** ** ****   * *   ** * **** *** ***
*  ** ***    * *   ** ** *   *     *   ** * * * *   *  *   ****    ** ** *  **  ** *   *  *** *  **   ***** ****  *** **** *****  * * *   ***   **    **   ** **  * *****   ***** * 
   *  *    * ****  ***   *   *  ** sum = ( 1) * (a1+a3+a5+a7+a9+a11);
    * ** *          *** *  **** ** sum2 =  (3) *  * *  *  * * *
**  *  *   *  * *      **   sum3 = sum + sum2;
 * **        * ***  ***     check = 10 - (sum3 % 10);
  *   ****  ** *** ** *** *   *    == a13)  {
 ** ****  ****    *     * *  *    **** *     **        **    * *       * ISBN");}
  * ** **** * ***    *   *  * * ***** ***    *   ***   * * **** **** *** ISBN");}
return 0;
}

Comments

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

Answer 7

Hidden content!
#include <stdio.h>
int main()
{
* **       ***    * ** **** *     ***  **  * 

 **  * *  *  * * **    * **    ** *** * *   *** ********    ***   *  **   **** *  ** * ****** ** *** **** * *      *** * **  *** ***  *******    *  *

** *** **  ** **** = **  *  * *   **  **  *  *** *  *  ***      *****   * * 




**   ** *  ** * (last==checkk)
*   ***  **   ******* *  **  ***  * * ******* ISBN");
  ** *  * * *** *** 
    ** ****** ***  * * * *  * ****  ****  *** ISBN");

   ***** ***        0;

}

Comments

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

Answer 8

Hidden content!
#include   ******    ** *  *
int main()
{
*  **    ** *   ***    * * *   *  **** ******  **  * ***   *** 
 **  *  * *****  * **  *****   *  **** **  * *     * *** *    ** * ** *** *  * **  **** *   * * *** *  * *** *  * ***      **  ***** *  *   *** ***  ****    **  * ** **     *** * *   *  ** 
*****   * *** **   *  *      sum = ( 1) * (a1+a3+a5+a7+a9+a11);
** *  ****  ** **** * ****  * sum2 =  (3) * (a2+a4+a6+a8+a10+a12);
**  ***  **  **  * *** **  *    sum3 = sum + sum2;
**** ** * * *  ***  **** *  check = 10 - (sum3 % 10);
** * * **    **  * *    ***      == a13)  {
  ** ** **   * **   *   ** **** ** *        ***** ** ** ****    * ***** *       *   *****
 *    * **  *  **     *  *** *** * *   *     **  *  **  *** *    ** *  * ***    *** **** **  *****
return 0;
}

Comments

prog.c: In function 'main':
prog.c:11:16: error: too many arguments for format [-Werror=format-extra-args]
         printf("Valid ISBN",check);}
                ^~~~~~~~~~~~
prog.c:12:22: error: too many arguments for format [-Werror=format-extra-args]
         else {printf("Invalid ISBN",check);}
                      ^~~~~~~~~~~~~~
cc1: all warnings being treated as errors

Answer 9

Hidden content!
#include<stdio.h>
int main()
{
 *   *  ***     *** *****  * *** **** a,b,c,d,e,f,g,h,i,j,k,l,m;
 *  *****  * * * **  **   *   * **  ***  *     * ** * *  *  ** *    *  ***  *   **   **  ** *  *  * ****    * * **  *****  ***  ** **   *** *     *  *** *  **** **  *    ***  *** **  

 *   *    ***** ***  * *  ***    **  
* **** *    ** * ** **    ****  *** 
******  * *    * ****   **  ** * * *  * 
** *  ***** **** *  * *   ** * 
* ***** * ****** ** *** **** *     ***    
* *    *****  *** ******* * **** *** * 
**  *  **  ***    ** *   *  * *   ***  ** 
********  ****  ** *   **   *  * **
*    ****   ***  ** *  ** *  * *  * 
***    ********  ******  **  * *** **  
  ** **** *  * ** ** *   * *   **** * *
*** ***   ** * **       **       

* **  * ***  ** * * **    **  *** ** (m==10-(a+b+c+d+e+f+g+h+i+j+k+l)%10)
 * ** ***    ***   *****   ** *  ** *
***      *** *    * ****   *  * *** *  *   *   ***** *  * * ***  ************  ISBN");
     }
**** * **  ***  * *  ** * * * * ***   
     {
* ** *  **  *  * * ** ***   * ******   **  **  *  * ** **** *  *     **    ** ** *  *  ISBN");
     }
}

Comments

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

Answer 10

Hidden content!
#include  **   *** *  **
int main()
{
**    ** *  *   ** * *****   ** *   *****   * **  * **     * *
 ** ** *  *    * * ***  ***** ***     *******  ****    **** *  *  **    * * * *     ***         * *   * * **  *   ****  *  * *** *    *    * **   *   *  *   **
 * * ****   *  **   *  *  * sum = ( 1) * (a1+a3+a5+a7+a9+a11);
 **     ** * *  **  * ***  * sum2 =  (3) * (a2+a4+a6+a8+a10+a12);
* * ** *  * *** ***** **** *  sum3 = sum + sum2;
  *   **** *****  * * * ** check = 10 - (sum3 % 10);
    **   * * * ***  **  * **     *  == a13)  {
 ** ***  **  * ****  *    ** ** ** *  *   * *  *** *    *     * **  *** *** *  * 
*** *  * * *    *  *     * *** ***  ***  *** * **   **   *   *  *****      *      ***** **  
return 0;
}

Comments

prog.c: In function 'main':
prog.c:11:16: error: too many arguments for format [-Werror=format-extra-args]
         printf("Valid ISBN",check);}
                ^~~~~~~~~~~~
prog.c:12:22: error: too many arguments for format [-Werror=format-extra-args]
         else {printf("Invalid ISBN",check);}
                      ^~~~~~~~~~~~~~
cc1: all warnings being treated as errors