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