0217 Contains Duplicate

Solved at: 230129

Question

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.

Solution

class Solution {    func containsDuplicate(_ nums: [Int]) -> Bool {        var set = Set<Int>()        for num in nums {            if set.contains(num) {                return true            }            else {                set.insert(num)            }        }        return false    }}

Results

• Runtime 642 ms Beats 44.57%
• Memory 19 MB Beats 10.85%

Complexity Analysis

Both $O(N)$

Takeaways

Using sorting can sacrifice time to $O(N \log N)$ and pull down space into $O(1)$