Solve three easy algorithm problems
Company: Apple
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: easy
Interview Round: Technical Screen
You are given three independent algorithmic tasks. For each one, explain your approach (no need to run code).
## 1) Merge two sorted lists (integers instead of nodes)
Given two sorted integer arrays `A` and `B` (non-decreasing order), merge them into a single sorted array containing all elements from both inputs.
- **Input:** two arrays `A`, `B`
- **Output:** merged sorted array
- **Constraints (typical):** `0 <= len(A), len(B) <= 1e5`
## 2) Max profit from one stock transaction
Given an array `prices` where `prices[i]` is the stock price on day `i`, compute the maximum profit you can achieve by choosing **at most one** day to buy and a later day to sell. If no profit is possible, return `0`.
- **Input:** array `prices`
- **Output:** integer max profit
- **Constraints (typical):** `1 <= n <= 1e5`, `0 <= prices[i] <= 1e9`
## 3) Validate parentheses pairing
Given a string `s` consisting only of the characters `'('`, `')'`, `'['`, `']'`, `'{'`, `'}'`, determine whether the parentheses/brackets are **valid**.
A string is valid if:
- Every opening bracket has a corresponding closing bracket of the same type.
- Brackets are closed in the correct order.
- **Input:** string `s`
- **Output:** boolean
- **Constraints (typical):** `0 <= |s| <= 1e5`
Quick Answer: This multi-part prompt evaluates proficiency in fundamental algorithmic concepts including sorted array handling, single-transaction optimization in time-series data, and bracket-sequence validation, measuring understanding of array and string manipulation, common data structures, algorithmic complexity, and edge-case reasoning.