ByteDance Hard Interview Questions

In ByteDance's social networking site, we need to model user relationships and find the most relevant connections for a given user in a depth-first manner.
You are to implement a function that takes the connections of users and a target user, returning all relevant connections.Method Signature: def find_relevant_connections(connections: Dict[str, List[str]], user: str) -> List[str]:
- connections: a dictionary where keys are user IDs and values are lists of user IDs representing friendships.
- user: a string representing the target user's ID.
- Returns a list of user IDs that are reachable from the target user.Example 1:
Input: connections = {'a': ['b', 'c'], 'b': ['d'], 'c': ['e'], 'd': [], 'e': []} and user = 'a'
Output: ['b', 'c', 'd', 'e']
Explanation: From user 'a', you can reach 'b', 'c', 'd', and 'e'.Example 2:
Input: connections = {'x': ['y'], 'y': ['z'], 'z': []} and user = 'x'
Output: ['y', 'z']
Explanation: User 'x' can reach 'y' and 'z'.Constraints:
- 1 <= len(connections) <= 10^4
- Each user ID has at most 100 characters.

In the dynamic environment of ByteDance's content platform, we need to efficiently generate a user feed that displays trending content based on real-time user interactions.
You are to implement a function that takes a list of user interactions (likes or comments) and generates a list of trending content using a sliding window approach.Method Signature: def generate_trending_feed(interactions: List[str], n: int) -> List[str]:
- interactions: a List of strings representing the IDs of content interacted with by a user.
- n: an integer representing the number of trending content items to return.
- Returns a List of strings containing the IDs of the trending content items.Example 1:
Input: interactions = ['a', 'b', 'a', 'c', 'b', 'a']
Output: ['a', 'b', 'c']
Explanation: Item 'a' is interacted with 3 times, 'b' 2 times, and 'c' 1 time.Example 2:
Input: interactions = ['x', 'y', 'y', 'x', 'x', 'z', 'y']
Output: ['x', 'y', 'z']
Explanation: 'x' has 3 interactions, 'y' has 3, and 'z' has 1.Constraints:
- 1 <= len(interactions) <= 10^4
- 1 <= n <= 100
- interactions[i] is a string with length 1 to 100.