List Buildings That Clear Every Building to Their Right
Company: Meta
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: medium
Interview Round: Other
### Problem
Buildings have heights `heights`, and the ocean lies to their right. A building sees the ocean exactly when every building to its right is strictly shorter. Return the zero-based indices of all such buildings in increasing order.
```cpp
class Solution {
public:
vector<int> findBuildings(vector<int>& heights);
};
```
### Examples
**Example 1:**
```text
heights = [6,2,5,5,1]
Output: [0,3,4]
Explanation: Equal height at index 3 blocks index 2.
```
**Example 2:**
```text
heights = [2,2,2]
Output: [2]
Explanation: Only the rightmost building has no equal-height obstruction.
```
### Constraints
- `1 <= heights.length <= 10^5`.
- Heights are integers in `[1,10^9]`.
### Clarifying Questions
Equal height blocks the view. Output indices must be increasing, even if the scan proceeds from right to left.
```hint Inspect the structure
How do equal-height buildings affect the visibility rule and the required output order?
```
### Reasoning checkpoints
- Apply strict right-side obstruction, including equal-height buildings.
- Return all and only the qualifying original indices in increasing order.
### Optional extensions
How would the answer change if equal-height buildings did not obstruct one another?
Overview: List Buildings That Clear Every Building to Their Right. Buildings have heights heights, and the ocean lies to their right. A building sees the ocean exactly when every building to its right is strictly shorter.