LeetCode 217 Contains Duplicate Solution in Python | Easy Interview Problem Tutorial

Solve LeetCode 217 "Contains Duplicate" in Python with this beginner-friendly tutorial! This easy problem asks you to check if any value appears at least twice in an integer array—return `true` if duplicates exist, `false` if all elements are distinct. We’ll use a clever one-liner with sets to crack examples like `[1, 2, 3, 1]` (true) and `[1, 2, 3, 4]` (false). Perfect for coding interview prep, Python learners, or anyone tackling LeetCode challenges step-by-step!

🔍 **What You'll Learn:**
- Understanding the Contains Duplicate problem
- Using sets to detect duplicates efficiently
- Writing a concise Python solution
- Testing with LeetCode test cases

💻 **Code Used in This Video:**
class Solution:
def containsDuplicate(self, nums):
# Type: List[int]
# rtype: bool
return len(nums) != len(set(nums)) # True if duplicates exist

# Test cases
print(Solution().containsDuplicate([1, 2, 3, 1])) # Output: True
print(Solution().containsDuplicate([1, 2, 3, 4])) # Output: False
print(Solution().containsDuplicate([1, 1, 1, 3, 3, 4, 3, 2, 4, 2])) # Output: True

🌟 **Why Solve LeetCode 217?**
This problem tests your grasp of sets and problem-solving—key skills for coding interviews at top tech companies! We’ll break down how `len(nums) != len(set(nums))` works (sets remove duplicates), explore edge cases, and share tips to optimize for LeetCode’s constraints (array length up to 10^5). Master this, and you’ll be ready for more array challenges—ideal for interview prep or Python practice!

📚 **Who’s This For?**
- Python beginners tackling LeetCode
- Coders prepping for tech interviews
- LeetCode enthusiasts solving easy problems

👍 Like, subscribe, and comment: What LeetCode problem should we solve next? Next up: Two Sum (LeetCode 1)—stay tuned!

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