Amazon Frontend Engineer Interview Questions

Amazon strives to provide relevant product recommendations based on user browsing history and preferences. Utilizing a two-pointer technique can efficiently pair and rank products for recommendations.
Given a sorted array of product ratings and a target value, find two indices such that their ratings add up to the target.
### Function Signature
python
find_product_pair(ratings: List[int], target: int) -> List[int]

### Example 1:
Input: ratings = [1, 2, 3, 4, 6], target = 6
Output: [1, 2]
Explanation: Ratings at indices 1 and 2 (i.e., 2 + 4) equal the target 6.
### Example 2:
Input: ratings = [2, 5, 9, 11], target = 11
Output: [0, 2]
### Constraints:
- 1 <= ratings.length <= 10^4
- -10^4 <= ratings[i] <= 10^4
- -10^4 <= target <= 10^4

In the fast-paced e-commerce environment, Amazon needs an efficient way to track price changes over time for various products. This feature enhances user engagement and informs purchasing decisions.
Given an array of product prices, implement a function that returns the maximum price within any k day window.
### Function Signature
python
max_price_in_window(prices: List[int], k: int) -> List[int]

### Example 1:
Input: prices = [100, 200, 150, 300, 250], k = 3
Output: [200, 300, 300]
Explanation: The maximum prices for the windows are 200 (days 1-3), 300 (days 2-4), and 300 (days 3-5).
### Example 2:
Input: prices = [120, 130, 115, 125, 140, 155], k = 2
Output: [130, 130, 125, 140, 155]
### Constraints:
- 1 <= prices.length <= 10^5
- 1 <= prices[i] <= 10^6
- 1 <= k <= prices.length

In order to optimize rendering performance in Amazon's web applications, a Virtual DOM is used for efficient updates. This problem involves designing the diffing algorithm which reconciles changes in a virtual representation of the DOM.
### Class Signature
python
class VirtualDOM {
def create_element(self, tag: str, props: dict, children: List[Union[str, 'VirtualDOM']]) -> None:
# Create a virtual DOM element
def diff(self, old_tree: 'VirtualDOM', new_tree: 'VirtualDOM') -> List[str]:
# Compute the difference between two trees
}
### Example Method Signatures
- create_element(tag: str, props: dict, children: List[Union[str, 'VirtualDOM']]) -> None: Creates a virtual DOM element.
- diff(old_tree: 'VirtualDOM', new_tree: 'VirtualDOM') -> List[str]: Returns a list of operations needed to update the DOM based on differences.### Example 1:
Input:
old_tree = create_element('div', {'id': '1'}, ['Hello', 'World'])
new_tree = create_element('div', {'id': '1'}, ['Hello', 'Amazon'])
Output: ['UPDATE_TEXT: 1, Amazon']
### Constraints:
- 1 <= number of elements in tree <= 1000
- Tags and props are limited to valid HTML attributes.