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