1762. Buildings With an Ocean View

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1762. Buildings With an Ocean View

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.

Constraints:

  • 1 <= heights.length <= 10^5
  • 1 <= heights[i] <= 10^9

Hints/Notes

Solution

Language: C++

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class Solution {
public:
    vector<int> findBuildings(vector<int>& heights) {
        int max_height = 0;
        vector<int> res;
        for (int i = heights.size() - 1; i >= 0; i--) {
            if (heights[i] > max_height) {
                res.push_back(i);
            }
            max_height = max(max_height, heights[i]);
        }
        ranges::reverse(res);
        return res;
    }
};