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