Editorial: Next Greater Element (Circular)

by admin · Oct. 18, 2026

1 Intuition

Simulate the wrap-around by scanning the array twice.

2 Approach

Use a monotonic decreasing stack of indices over 2n steps, only pushing during the first pass.

3 Complexity Analysis

Time O(n), Space O(n).

4 Solution Code

class Solution:
    def nextGreaterElements(self, nums: list[int]) -> list[int]:
        n = len(nums)
        out, stack = [-1] * n, []
        for i in range(2 * n):
            x = nums[i % n]
            while stack and nums[stack[-1]] < x:
                out[stack.pop()] = x
            if i < n:
                stack.append(i)
        return out

5 Code Walkthrough

The reference solution below implements the approach step by step.