Contains Duplicate

Difficulty: Easy · Topic: Hashing

Given an integer array nums, return True if any value appears at least twice, and False if every element is distinct.

Examples

contains_duplicate([1,2,3,1])
→ true

1 appears twice.

contains_duplicate([1,2,3,4])
→ false

contains_duplicate([1,1,1,3,3,4,3,2,4,2])
→ true

Target complexity: time O(n), space O(n)

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