523

WINDOW = 2

class Solution:
    def checkSubarraySum(self, nums: List[int], k: int) -> bool:
        N = len(nums)
        if N < WINDOW:
            return False

        seen = {0}

        window = deque()
        cur_sum = 0
        for i, n in enumerate(nums):
            cur_sum = (cur_sum + n) % k

            window.append(cur_sum)

            if i >= WINDOW - 1:
                if cur_sum in seen:
                    return True

                seen.add(window.popleft())

        return False