Method containsNearbyDuplicate

java/0219-contains-duplicate-ii.java:2–21

(int[] nums, int k)

class Solution {
    public boolean containsNearbyDuplicate(int[] nums, int k) {
        
        Set<Integer> window = new HashSet<>();
        int left = 0;
        for (int right = 0; right < nums.length; right++) {

            if (window.size() > k) {
                window.remove(nums[left]);
                left++;
            }

            if (window.contains(nums[right])) {
                return true;
            }

            window.add(nums[right]);
        }

        return false;
    }
}