219. Contains Duplicate II

  public static boolean containsNearbyDuplicate(int[] nums, int k) {        if(nums == null || nums.length == 0) {            return false;        }        boolean find = false;        Set<Integer> set = new HashSet<>();        int i = 0;        for(i = 0; i < nums.length; i++) {            if(!set.add(nums[i])) {                if(isDistictK(nums, nums[i], i, k)) {                    find = true;                    break;                }else {                    continue;                }            }        }        return find;    }    public static boolean isDistictK(int[] a, int num, int next,int distict) {        int i = 0;        boolean find = false;        for(i = 0; i < a.length; i++) {            if(i >= next) {                break;            }            if(a[i] == num && i != next) {                if(next - i > distict) {                    continue;                }else {                    find = true;                    break;                }            }        }        return find;    }