import java.util.*;

/**
 * Codes demonstrates the use of queues to encrypt and decrypt messages.
 *
 * @author Lewis and Chase
 * @version 4.0
 */
public class Codes
{
    /**
     * Encode and decode a message using a key of values stored in
     * a queue.
     */
    public static void main(String[] args)
    { 
        int[] key = {5, 12, -3, 8, -9, 4, 10};
        Integer keyValue;
        String encoded = "", decoded = "";
        String message = "All programmers are playwrights and all " +
                     "computers are lousy actors.";
        Queue<Integer> encodingQueue = new LinkedList<Integer>();
		Queue<Integer> decodingQueue = new LinkedList<Integer>();
    
        // load key queues 
        for (int scan = 0; scan < key.length; scan++)
        {
            encodingQueue.add(key[scan]);
            decodingQueue.add(key[scan]);
		}
    
        // encode message 
        for (int scan = 0; scan < message.length(); scan++)
        {
	        keyValue = encodingQueue.remove();
            encoded += (char) (message.charAt(scan) + keyValue);
            encodingQueue.add(keyValue);
        }
    
        System.out.println ("Encoded Message:\n" + encoded + "\n");
    
        // decode message 
        for (int scan = 0; scan < encoded.length(); scan++)
        {
            keyValue = decodingQueue.remove();
            decoded += (char) (encoded.charAt(scan) - keyValue);
            decodingQueue.add(keyValue);
        }
    
        System.out.println ("Decoded Message:\n" + decoded);
    }
}