Problem description:

There are n buildings in a line. You are given an integer array heights of size n that represents the heights of the buildings in the line.

The ocean is to the right of the buildings. A building has an ocean view if the building can see the ocean without obstructions. Formally, a building has an ocean view if all the buildings to its right have a smaller height.

Return a list of indices (0-indexed) of buildings that have an ocean view, sorted in increasing order.

Example 1:

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Input: heights = [4,2,3,1]
Output: [0,2,3]
Explanation: Building 1 (0-indexed) does not have an ocean view because building 2 is taller.

Example 2:

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Input: heights = [4,3,2,1]
Output: [0,1,2,3]
Explanation: All the buildings have an ocean view.

Example 3:

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Input: heights = [1,3,2,4]
Output: [3]
Explanation: Only building 3 has an ocean view.

Example 4:

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Input: heights = [2,2,2,2]
Output: [3]
Explanation: Buildings cannot see the ocean if there are buildings of thesame height to its right.

Solution:

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class Solution:
    def findBuildings(self, heights: List[int]) -> List[int]:
        res = [len(heights)-1]
        cur_max = heights[-1]
        for i in range(len(heights)-2, -1, -1):
            if heights[i] > cur_max:
                res.append(i)
                cur_max = heights[i]
        return res[::-1]

time complexity: $O(n)$
space complexity: $O(n)$
reference:
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