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