# Unobstructed Buildings - Facebook Top Interview Questions

### Problem Statement :

```You are given a list of integers heights representing building heights.

A building heights[i] can see the ocean if every building on its right has shorter height.

Return the building indices where you can see the ocean, in ascending order.

Constraints

0 ≤ n ≤ 100,000 where n is the length of heights

Example 1

Input

heights = [1, 5, 5, 2, 3]

Output

[2, 4]

Explanation

We can see the ocean in building heights[2] and heights[4].

Example 2

Input

heights = [5, 4, 3, 2, 1]

Output

[0, 1, 2, 3, 4]

Explanation

We can see the ocean in every building since each building is taller than every other on its right.

Example 3

Input

heights = [1, 1, 1, 1, 1]

Output

[4]

Explanation

We can't see the ocean in any building other than the last one.```

### Solution :

```                        ```Solution in C++ :

vector<int> solve(vector<int>& heights) {
vector<int> ret;
int maxi = INT_MIN;
for (int i = heights.size() - 1; i >= 0; i--) {
if (maxi < heights[i]) {
maxi = heights[i];
ret.push_back(i);
}
}
reverse(ret.begin(), ret.end());
return ret;
}```
```

```                        ```Solution in Java :

import java.util.*;

class Solution {
public int[] solve(int[] heights) {
int N = heights.length;
int[] max = new int[N + 1];
for (int i = N - 1; i >= 0; i--) max[i] = Math.max(max[i + 1], heights[i]);
ArrayList<Integer> ans = new ArrayList<Integer>();
for (int i = 0; i < N; i++) {
if (heights[i] > max[i + 1])
}
return convert(ans);
}

public int[] convert(ArrayList<Integer> arr) {
int[] ans = new int[arr.size()];
for (int i = 0; i < arr.size(); i++) ans[i] = arr.get(i);
return ans;
}
}```
```

```                        ```Solution in Python :

class Solution:
def solve(self, heights):
ans = []
highest = -1
for i in range(len(heights) - 1, -1, -1):
if heights[i] > highest:
ans.append(i)
highest = heights[i]
return ans[::-1]```
```

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