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