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