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