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