Contains Duplicate II - LeetCode : Swift

Contains Duplicate II - LeetCode

Given an integer array nums and an integer k, return true if there are two distinct indices i and j in the array such that nums[i] == nums[j] and abs(i - j) <= k.

Example 1:

Input: nums = [1,2,3,1], k = 3
Output: true

Example 2:

Input: nums = [1,0,1,1], k = 1
Output: true

Example 3:

Input: nums = [1,2,3,1,2,3], k = 2
Output: false

Constraints:

• 1 <= nums.length <= 10^5
• -10^9 <= nums[i] <= 10^9
• 0 <= k <= 10^5

Solution

class Solution {
    func containsNearbyDuplicate(_ nums: [Int], _ k: Int) -> Bool {
        var hash: [Int: Int] = [:]

        for i in 0..<nums.count {
            if let value = hash[nums[i]], abs(value - i) <= k {
                return true
            } else {
                hash[nums[i]] = i
            }
        }
        return false
    }
}