Arrays & Strings — The Complete MAANG Interview Guide (100 Problems)

Introduction

Arrays and Strings form the foundation of every technical interview. They appear in every MAANG/FAANG screening round and understanding their core patterns lets you crack 40% of all LeetCode problems.

• Why Arrays & Strings Are Critical
• The 7 Core Patterns
• Difficulty Distribution (100 Problems)
• Roadmap Index

Why Arrays & Strings Are Critical

• Frequency: ~35% of all FAANG coding rounds start with an array/string problem
• Pattern reuse: Prefix sum, two pointers, and sliding window appear across Trees, Graphs, and DP problems too
• Interview signal: Clean O(n) solutions demonstrate algorithmic maturity

The 7 Core Patterns

Difficulty Distribution (100 Problems)

• 🟢 Easy (1–25): Foundation — must solve in < 10 minutes
• 🟡 Medium (26–75): Core interview level — 20–30 minutes
• 🔴 Hard (76–100): Senior/Staff bar — 40–45 minutes

Each problem in this series includes:

1. Problem statement + examples
2. Intuition walkthrough
3. Full solutions in C, C++, Java, JavaScript, Python
4. Time & Space complexity
5. Edge cases & follow-ups

Roadmap Index

Start with Problem 1 — Two Sum →