Implement array and tree traversal tasks

You are interviewing for a storage/infra-leaning role. Solve the following coding tasks and be ready to discuss time/space complexity and edge cases.

Task A: Max profit from one trade

Given an integer array prices where prices[i] is the price of a stock on day i, compute the maximum profit achievable by choosing at most one buy day b and one sell day s with b < s. If no profit is possible, return 0.

• Input: prices: int[]
• Output: max_profit: int
• Constraints (typical): 1 <= n <= 2e5 , prices fit in 32-bit int

Follow-ups:

• What is the best achievable time and space complexity?
• How do you handle monotonically decreasing prices?

Task B: Right-side view of a binary tree

Given the root of a binary tree, return the list of node values visible when the tree is viewed from the right side (from top level to bottom level).

• Input: root (binary tree node)
• Output: right_view: int[]

Follow-ups:

• Compare DFS vs BFS approaches and their complexities.
• What are edge cases (empty tree, skewed tree, very deep tree)?

Discussion (no coding required, but explain clearly)

• If the code were used in a multi-threaded environment or under very large datasets , what assumptions break and what changes (if any) would you make?