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