1762. Buildings With an Ocean View

O(n) time O(n) space

class Solution {
public:
    vector<int> findBuildings(vector<int>& heights) {
        vector<int> res;
        for (int n = size(heights), i = 0; i < n; ++i) {
            while (!empty(res) && heights[res.back()] <= heights[i]) {
                res.pop_back();
            }
            res.push_back(i);
        }
        return res;
    }
};