1762. Buildings With an Ocean View

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: 
Explanation: Only building 3 has an ocean view.```

Example 4:

```Input: heights = [2,2,2,2]
Output: 
Explanation: Buildings cannot see the ocean if there are buildings of the same height to its right.```

Constraints:

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

1762. Buildings With an Ocean View
``````struct Solution;

impl Solution {
fn find_buildings(heights: Vec<i32>) -> Vec<i32> {
let mut stack = vec![];
let n = heights.len();
for i in 0..n {
while let Some(&j) = stack.last() {
if heights[j] <= heights[i] {
stack.pop();
} else {
break;
}
}
stack.push(i);
}
stack.into_iter().map(|i| i as i32).collect()
}
}

#[test]
fn test() {
let heights = vec![4, 2, 3, 1];
let res = vec![0, 2, 3];
assert_eq!(Solution::find_buildings(heights), res);
let heights = vec![4, 3, 2, 1];
let res = vec![0, 1, 2, 3];
assert_eq!(Solution::find_buildings(heights), res);
let heights = vec![2, 2, 2, 2];
let res = vec!;
assert_eq!(Solution::find_buildings(heights), res);
}
``````