public class MyTestClass {

    private char target = 'O';
    private String input =  "OXXXXXXXXXXXXXXXXXXX\n" +
                            "XXXXXXXXXXXXXXXXXXXX\n" +
                            "XXXXXXXXXXXXXXOOOOOO\n" +
                            "XXXXOXXXXXXXXXXXXXXX\n" +
                            "XXXXXXXXXXXXXXXXXXXX\n" +
                            "XXXXXXXXXXXXXXXXXXXX\n" +
                            "XXXXXXXXXXXXXXXXXXXX\n" +
                            "XXXXXXXXXXXXXXXXXXXX\n" +
                            "XXXXXXXXXOOOXXXXXXXX\n" +
                            "XXXXXXXXXOXOXXXXXXXX\n" +
                            "XXXXXXXXXOOOXXXXXXXX\n" +
                            "XXXXXXXXXXXXXXXXXXXX\n" +
                            "XXXXXXXXXXXXXXXXXXXX\n" +
                            "XXXXXXOOXXXXXXXXXXXX\n" +
                            "XXXXXXOOXXXXXXXXXXXX\n" +
                            "XXXXXXXXOOXXXXXXXXXX\n" +
                            "XXXXXXXXOOOOXXXXXXXX\n" +
                            "XXXXXXXXXXXXXXXXXXXX\n" +
                            "XXXXXXXXXXXXXXXXXXXX\n" +
                            "XXXXXXXXXXXXXXXXXXXO";

    @Test
    public void count() {
        String[] str = input.split("\n");
        int h = str.length;
        int w = str[0].length();
        char[][] chars = new char[h][w];
        for (int i = 0; i < h; i++) {
            char[] charsInRow = str[i].toCharArray();
            System.arraycopy(charsInRow, 0, chars[i], 0, w);
        }

        Map<Point, ArrayList<Point>> islandMap = new HashMap<>();

        for (int i = 0; i < h; i++) {
            for (int j = 0; j < w; j++) {

                char c = chars[i][j];
                if(c == target) {
                    Point firstPoint = new Point(j, i);

                    int iLeft = i;
                    int jLeft  = j - 1;

                    Point left = new Point(jLeft, iLeft);

                    int iTop = i - 1;
                    int jTop  = j;

                    Point top = new Point(jTop, iTop);

                    boolean addedToList = false;

                    for (Point key : islandMap.keySet()) {
                        ArrayList<Point> points = islandMap.get(key);

                        if (points != null && (points.contains(left) || points.contains(top))) {
                            points.add(firstPoint);
                            addedToList = true;
                        }
                    }

                    if (!addedToList) {
                        ArrayList<Point> list = new ArrayList<>();
                        list.add(firstPoint);
                        islandMap.put(firstPoint, list);
                    }
                }
            }
        }

        System.out.println(islandMap.keySet().size());
        int biggest = 0;
        for (List<Point> lists : islandMap.values()) {
            if (biggest <= lists.size()) {
                biggest = lists.size();
            }
        }
        System.out.println(biggest);
    }

    class Point {
        int x, y;

        @Override
        public String toString() {
            return "{" +
                    "\"x\":" + x +
                    ", \"y\":" + y +
                    '}';
        }

        public Point(int x, int y) {
            this.x = x;
            this.y = y;
        }

        @Override
        public boolean equals(Object o) {
            if (this == o) return true;
            if (o == null || getClass() != o.getClass()) return false;
            Point point = (Point) o;
            return x == point.x &&
                    y == point.y;
        }

        @Override
        public int hashCode() {
            return Objects.hash(x, y);
        }
    }
}