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