0217 Contains Duplicate

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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

swift

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 $O(1)$

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