Contains Duplicate (LeetCode) — Hindi Walkthrough

Contains Duplicate problem solved step-by-step in Hindi. Set-based O(n) solution with practice.

What you'll learn

Quick win — use a set to detect duplicates in O(n) time and space. Hindi explanation, code in three languages, complexity discussion, and a few variants you should know.

Why Techwave Academy

• 100% free — no credit card, no upsells on the core curriculum.
• In-browser IDE — write and run code without installing anything.
• AI mentor — 24×7 doubt clearing in plain language.
• India-first — Hindi/Hinglish narration where useful, CBSE alignment for school courses.
• Built by working software engineers — not theoreticians.

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