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