CodeEasy v0.1

Contains Duplicate

Easy Subject: Arrays & Hashing
Time Complexity
O(N)
Space Complexity
O(N)

Problem Description

Given an integer array nums, return true if any value appears at least twice in the array, and return false if every element is distinct.

Optimal Solution

Python 
def containsDuplicate(nums):
    seen = set()
    for num in nums:
        if num in seen:
            return True
        seen.add(num)
    return False