class Solution {
    public List<List<Integer>> findContinuousSequence(int sum) {
        int[] prefixSum = new int[sum / 2 + 2];
        for (int i = 1; i <= sum / 2 + 1; i++) {
            prefixSum[i] = prefixSum[i - 1] + i;
        }

        List<List<Integer>> ans = new LinkedList<>();
        for (int i = 2, j = 1; i <= sum / 2 + 1 && j < i; i++) {
            while (prefixSum[i] - prefixSum[j - 1] > sum) {
                j++;
            }
            if (prefixSum[i] - prefixSum[j - 1] == sum) {
                List<Integer> m = new ArrayList<>(i - j + 1);
                for (int x = j; x <= i; x++) {
                    m.add(x);
                }
                ans.add(m);
            }
        }
        return ans;
    }
}