// 41 ms, runtime beats 53.07 % of java submissions.
class Solution {
    public int[] nextLargerNodes(ListNode head) {
        ArrayList<Integer> r = new ArrayList<>();

        Map<ListNode, Integer> map = new HashMap<>();

        ListNode c = head;
        while (c != null) {
            if (!map.containsKey(c)) nextMax(c, map);

            r.add(map.get(c));
            c = c.next;
        }

        int[] result = new int[r.size()];
        for (int i = 0; i < result.length; i++) result[i] = r.get(i);
        return result;
    }

    private ListNode nextMax(ListNode from, Map<ListNode,Integer> map) {
        ListNode next = from.next;
        while (next != null) {
            if (next.val > from.val){
                map.put(from, next.val);
                return next;
            }
            next = nextMax(next, map);
        }
        map.put(from, 0);
        return null;
    }
}