/*

* Noah Becker

* Marriotts Ridge High School

* contest 4 Junior

* Reg Hahne

*/

import java.io.File;

import java.util.Scanner;

import java.io.IOException;

public class MatrixEncryptionClient

{

public static void main(String[] args) throws IOException

{

//connecting to the file

String pathToFile = "G:";

File inFile = new File(pathToFile, "matrixjr.txt");

Scanner inData = new Scanner(inFile);

//declaring variables

String line = "", message, matrixNums, codedMessage = "", letter1, letter2;

int a, b, c, d;

//processing data

for(int input = 0;input < 5;input++)

{

codedMessage = "";

line = inData.nextLine();

message = line.substring(0, line.length() - 8);

matrixNums = line.substring(line.length() - 8,line.length());

matrixNums = matrixNums.replaceAll(" ","");

a = Integer.valueOf(matrixNums.substring(0, 1));

b = Integer.valueOf(matrixNums.substring(1, 2));

c = Integer.valueOf(matrixNums.substring(2, 3));

d = Integer.valueOf(matrixNums.substring(3, 4));

if(message.length() % 2 != 0)

message += " ";

for(int i = 0; i < message.length();i+=2)

{

letter1 = message.substring(i, i + 1);

letter2 = message.substring(i + 1, i+ 2);

codedMessage += change2letters(letter1, letter2, a, b, c, d);

}

System.out.println(codedMessage);

}

}

//this method will encrypt 2 letters at a time

public static String change2letters(String l1, String l2, int a, int b,int c, int d)

{

int num1 = 0, num2 = 0;

String[] alphabet = {"A", "B", "C", "D", "E", "F", "G", "H", "I", "J", "K", "L", "M",

"N", "O", "P", "Q", "R", "S", "T", "U", "V", "W", "X", "Y", "Z", " "};

for(int index = 0;index < 27;index++)

{

if(l1.equals(alphabet[index]))

num1 = index + 1;

if(l2.equals(alphabet[index]))

num2 = index + 1;

}

return changeBacktoWords(num1, num2, a, b, c, d, alphabet);

}

//this method will switch the numbers back into words in the form of a coded message

public static String changeBacktoWords(int num1, int num2, int a, int b, int c, int d, String[] alphabet)

{

String letter1 = "", letter2 = "";

int holder = num1;

num1 = a * num1 + b * num2;

num2 = c * holder + d * num2;

if(num1 != 27)

letter1 = alphabet[(num1 % 27) - 1];

else

letter1 = " ";

if(num2 != 27)

letter2 = alphabet[(num2 % 27) - 1];

else

letter2 = " ";

return letter1 + letter2;

}

}

/*

LRQBVNOE

XKIXBQUB

KEKW

RNC RAIMEJEGPE

ROUTKSBAECPXECIX

*/