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