题解 | 单调栈

class Solution:
    def foundMonotoneStack(self , nums: List[int]) -> List[List[int]]:
        ans = []
        for i in range(len(nums)):
            l, r = i-1, i+1
            while l >= 0:
                if nums[l] >= nums[i]:
                    l -= 1
                else:
                    break

            while r < len(nums):
                if nums[r] >= nums[i]:
                    r += 1
                else:
                    break
            if r == len(nums):
                r = -1
            ans.append([l,r])
        return ans