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