List<Double> quadraticEquation(int a, int b, int c) {
int det = b * b - 4 * a * c;
List<Double> res = new ArrayList<>();
if (det > 0) {
res.add((-b - Math.sqrt(det)) / (2 * a));
res.add((-b + Math.sqrt(det)) / (2 * a));
} else if (det == 0) {
res.add((double)-b / (2 * a));
}
Collections.sort(res);
return res;
}