Struggling with duplicate detection problems in coding interviews? This video explains LeetCode 217 - Contains Duplicate using a Hash Set — visually, step by step.
What you'll learn:
✅ Why brute force is O(n²) and how Hash Set gives you O(n)
✅ How the "seen" set tracks elements in a single pass
✅ Visual walkthrough with input array [1, 2, 3, 1]
✅ Clean Python implementation you can use in interviews
This is one of the most common warm-up problems asked in AI/ML engineering interviews.
Practice this problem yourself:
👉 https://codedive.in/contains-duplicate
🚀 codedive.in has 207 curated DSA problems for AI/ML engineers — with visual explanations, solutions in Python, and interview notes.
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⏱ Timestamps:
0:00 - Problem Statement
0:30 - Brute Force Approach
1:00 - Hash Set Intuition
1:30 - Visual Walkthrough
2:15 - Python Code
2:45 - Time & Space Complexity
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