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