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