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