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