Day06.java

//part 1
package org.thehuglio;

import java.io.File;


public class Main {
    private static final Reader reader = new Reader(new File("data.txt"));

    public static void main(String[] args) {
        System.out.println(reader.data);
        char c1 = 0;
        char c2 = 0;
        char c3 = 0;
        char c4 = 0;
        int counter = -1;
        for (char c : reader.data.get(0).toCharArray()) {
            counter++;
            if (c == c1 || c == c2 || c == c3 || c == c4 || c1 == c2 || c1 == c3 || c1 == c4 || c2 == c3 || c2 == c4 || c3 == c4 || c4 == 0) {
                c4 = c3;
                c3 = c2;
                c2 = c1;
                c1 = c;
            } else {
                System.out.println(counter);
                break;
            }
        }
    }
}
//part 2
package org.thehuglio;

import java.io.File;
import java.util.LinkedList;
import java.util.List;
import java.util.Objects;


public class Main {
    private static final Reader reader = new Reader(new File("data.txt"));

    public static void main(String[] args) {
        System.out.println(reader.data);
        int counter = 0;
        List<String> charlist = new LinkedList<>();
        for (char c : reader.data.get(0).toCharArray()) {
            counter++;
            charlist.add(0,String.valueOf(c));
            if (charlist.size() == 15) {
                charlist.remove(14);
            }
            boolean check = true;
            boolean first = true;
            for (String c1 : charlist) {
                first = true;
                for (String c2 : charlist) {
                    if (Objects.equals(c1, c2)) {
                        if (first) {
                            first = false;
                        } else {
                            check = false;
                            break;
                        }
                    }
                }
            }
            if (check && counter > 14) {
                System.out.println(counter);
                break;
            }
        }
    }
}