TreasureFinder

package Lection8;

import java.util.ArrayList;
import java.util.List;
import java.util.Scanner;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

public class TreasureFinder {
    public static void main(String[] args) {
        Scanner scan = new Scanner(System.in);
        String[] key = scan.nextLine().split("\\s+");
        String line = scan.nextLine();
        List<String> messages = new ArrayList<>();

        while (!line.equals("find")){
            messages.add(line);
            line = scan.nextLine();
        }

        for (int k = 0; k < messages.size(); k++) {
            String encryptedStr = "";
            int j = 0;
            for (int i = 0; i < messages.get(k).length(); i++) {
                char symbol = messages.get(k).charAt(i);
                symbol -= key[j].charAt(0) - '0';
                encryptedStr += symbol;
                j++;
                if (j == key.length){
                    j = 0;
                }
            }
            messages.set(k, encryptedStr);
        }

        Pattern treasure = Pattern.compile("&(?<treasure>[A-Za-z]+)&");
        Pattern coordinates = Pattern.compile("<(?<coordinates>[A-Z0-9]+)>");

        for (String message : messages) {
            Matcher matchTreasure = treasure.matcher(message);
            Matcher matchCoord = coordinates.matcher(message);
            if (matchTreasure.find() && matchCoord.find()){
                System.out.println(String.format("Found %s at %s",
                        matchTreasure.group("treasure"),
                        matchCoord.group("coordinates")));
            }
        }


    }
}