503. 下一个更大元素 II

503. 下一个更大元素 II

class Solution {
    public int[] nextGreaterElements(int[] nums) {
        if (nums == null || nums.length == 0)
            return new int[0];
        int len = nums.length;
        Deque<Integer> stack = new LinkedList<>();
        int[] ans = new int[len];
        Arrays.fill(ans, -1);
        for (int i = 0; i < 2 * len - 1; i++) {
            while (!stack.isEmpty() && nums[i % len] > nums[stack.peek()]) {
                ans[stack.pop()] = nums[i % len];
            }
            stack.push(i % len);
        }
        return ans;
    }
}