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