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