# 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:

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:

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


Example 3:

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


Constraints:

• 1 <= heights.length <= 105
• 1 <= heights[i] <= 109

## Solutions

• class Solution {
public int[] findBuildings(int[] heights) {
int n = heights.length;
List<Integer> ans = new ArrayList<>();
int mx = 0;
for (int i = heights.length - 1; i >= 0; --i) {
if (heights[i] > mx) {
mx = heights[i];
}
}
Collections.reverse(ans);
return ans.stream().mapToInt(Integer::intValue).toArray();
}
}

• class Solution {
public:
vector<int> findBuildings(vector<int>& heights) {
vector<int> ans;
int mx = 0;
for (int i = heights.size() - 1; ~i; --i) {
if (heights[i] > mx) {
ans.push_back(i);
mx = heights[i];
}
}
reverse(ans.begin(), ans.end());
return ans;
}
};

• class Solution:
def findBuildings(self, heights: List[int]) -> List[int]:
ans = []
mx = 0
for i in range(len(heights) - 1, -1, -1):
if heights[i] > mx:
ans.append(i)
mx = heights[i]
return ans[::-1]


• func findBuildings(heights []int) (ans []int) {
mx := 0
for i := len(heights) - 1; i >= 0; i-- {
if v := heights[i]; v > mx {
ans = append(ans, i)
mx = v
}
}
for i, j := 0, len(ans)-1; i < j; i, j = i+1, j-1 {
ans[i], ans[j] = ans[j], ans[i]
}
return
}

• function findBuildings(heights: number[]): number[] {
const ans: number[] = [];
let mx = 0;
for (let i = heights.length - 1; ~i; --i) {
if (heights[i] > mx) {
ans.push(i);
mx = heights[i];
}
}
return ans.reverse();
}


• /**
* @param {number[]} heights
* @return {number[]}
*/
var findBuildings = function (heights) {
const ans = [];
let mx = 0;
for (let i = heights.length - 1; ~i; --i) {
if (heights[i] > mx) {
ans.push(i);
mx = heights[i];
}
}
return ans.reverse();
};