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