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