lights.java

public class LightsOut {
	private List<Integer> board;
	
	public LightsOut() {
		board = generateBoard();
		while (!validateBoard()) {
			board = generateBoard();
		}
	}

	public List<Integer> getBoard() {
		return board;
	}
	
	private List<Integer> generateBoard() {
		int random = ThreadLocalRandom.current().nextInt(0, (int) Math.pow(2, 25));
		
		List<Integer> vector = new ArrayList();
		
		for (int i = 0; i < 25; i++) {
			vector.add(0, random % 2);
			random /= 2;
		}
	    
		return vector;
	}
	
	private Integer dot(List<Integer> a, List<Integer> b) {
		int product = 0;
		
		for (int i = 0; i < a.size(); i++) {
			product += a.get(i) * b.get(i);
		}
		
		return product;
	}
	
	private Boolean validateBoard() {
		List<Integer> a = List.of(0, 0, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0, 1, 1, 1, 0, 1, 0, 1, 0, 1, 1, 1, 0);		
		List<Integer> b = List.of(1, 0, 1, 0, 1, 1, 0, 1, 0, 1, 0, 0, 0, 0, 0, 1, 0, 1, 0, 1, 1, 0, 1, 0, 1);
		return dot(a, board) == 0 && dot(b, board) == 0;
	}
	
	public static void main(String[] args) {
		LightsOut game = new LightsOut();
		System.out.println(game.getBoard());
	}
}