ISBN-13 is a new standard for identifying books. It uses 13 digits d1d2d3d4d5d6d7d8d9d10d11d12d13. The last digit d13 is a checksum, which is calculated from the other digits using the following formula: 10 - (d1 + 3d2 + d3 + 3d4 + d5 + 3d6 + d7 + 3d8 + d9 + 3d10 + d11 + 3d12) % 10 If the checksum is 10, replace it with 0. Your program should read the input as a string. Display “invalid input” if the input is incorrect.

ISBN-13 is a new standard for identifying books. It uses 13 digits d1d2d3d4d5d6d7d8d9d10d11d12d13. The last digit d13 is a checksum, which is calculated from the other digits using the following formula:

10 - (d1 + 3d2 + d3 + 3d4 + d5 + 3d6 + d7 + 3d8 + d9 + 3d10 + d11 + 3d12) % 10

If the checksum is 10, replace it with 0. Your program should read the input as a string.

Display “invalid input” if the input is incorrect.

Program

import java.util.*;

public class Investment {

    public static void main(String args[]) {

     System.out.print("Enter the first 12 digits of an ISBN-13 as a string:");

     Scanner sc=new Scanner(System.in);

   String s = sc.next();

  int sum = 0;

    if (s.length() != 12)

    {

   System.out.println(s + " is an invalid input");

   System.exit(0);

  }

  for (int i = 0; i < s.length(); i++) 

  {

   if ((i + 1) % 2 == 0) 

     sum += 3 * (s.charAt(i) - '0');

    else 

    sum += s.charAt(i) - '0';

  }

    sum=sum%10;

    sum=10-sum;

    if(sum==10)

    s=s+"0";

    else

    s=s+sum;

   sum = (10 - sum%10)%10;

  

  System.out.println("The ISBN-13 number is " +s );

}

}

Result

Enter the first 12 digits of an ISBN-13 as a string: 978013213080

The ISBN-13 number is 9780132130806