[LeetCode]219 Contains Duplicate II

Given an array of integers and an integer k, find out whether there are two distinct indices i and j in the array such that nums[i] = nums[j] and the absolute difference between i and j is at most k.

Simple Java solution

public boolean containsNearbyDuplicate(int[] nums, int k) {        Set<Integer> set = new HashSet<Integer>();        for(int i = 0; i < nums.length; i++){            if(i > k) set.remove(nums[i-k-1]);            if(!set.add(nums[i])) return true;        }        return false; }