string output = "";
for (int i = 0; i < points.length - 2; i += 2) {
    output += points[i] == points[i + 2]
        ? points[i + 1] > points[i + 3]
            ? "1"
            : "3"
        ? points[i] > points[i + 2]
            ? "4"
            : "2";
}
return output;