class Solution {
    public int[] nextGreaterElements(int[] nums) {
        int len = nums.length;
        int[] results = new int[len];
        Arrays.fill(results, -1);

        PriorityQueue<Element> waiting = new PriorityQueue<>();
        waiting.add(new Element(0, nums[0]));

        for (int k = 1; k < 2*len; k++) {
            Element top = waiting.peek();
            if (top.position <= k - len) {
                waiting.poll();
                top = waiting.peek();
            }

            int current = nums[k >= len ? k-len: k];

            if (current > top.value) {
                for (Element element: waiting) {
                    int p = element.position;
                    results[p >= len ? p-len: p] = current;
                }

                waiting.clear();
            }

            waiting.add(new Element(k, current));
        }

        return results;
    }

    private class Element implements Comparable<Element> {
        public int position;
        public int value;

        public Element(int position, int value) {
            this.position = position;
            this.value = value;
        }

        public int compareTo(Element another) {
            return value - another.value;
        }
    }
}