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