Leetcode 1762 Buildings With an Ocean View

Problem statement

https://leetcode.com/problems/buildings-with-an-ocean-view/

Solution

The idea is to start from the ocean and add elements to stack only if they bigger than last element in the stack. In the end return reversed stack.

Complexity

Time and space complexity is O(n).

Code

class Solution:
    def findBuildings(self, H):
        n, ans = len(H), []
        for i in range(n-1, -1, -1):
            if not ans or H[i] > H[ans[-1]]:
                ans += [i]
                
        return ans[::-1]