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