Answer:
In Java:
import java.util.*;
public class Main{
public static void main(String[] args) {
Scanner input = new Scanner(System.in);
String isbn;
System.out.print("First 1:2 digits: ");
isbn = input.nextLine();
if(isbn.length()==12){
int chksum = 0;
for(int i = 0; i<12;i++){
if((i+1)%2==0){ chksum+= 3 * Character.getNumericValue(isbn.charAt(i)); }
else{ chksum+=Character.getNumericValue(isbn.charAt(i)); } }
chksum%=10;
chksum=10-chksum;
if(chksum==10){
System.out.print("The ISBN-13 number is "+isbn+"0");}
else{
System.out.print("The ISBN-13 number is "+isbn+""+chksum); } }
else{
System.out.print("Invalid Input");
} }}
Explanation:
See attachment for explanation where comments are used to explain each line
The only one of those I would trust is the site ending with EDU I hope this helps you.
That is encryption. Encrypted files usually have a password assigned. In order to decrypt the file, you need to have the password.
