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