Leetcode: Contains Duplicate III

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

 1 public class Solution {
 2     public boolean containsNearbyAlmostDuplicate(int[] nums, int k, int t) {
 3         if (nums==null || nums.length<2 || k<1 || t<0) return false;
 4         SortedSet<Long> set = new TreeSet<Long>();
 5         for (int i=0; i<nums.length; i++) {
 6             long lowerBound = (long)nums[i]-t;
 7             long upperBound = (long)nums[i]+t+1;
 8             SortedSet<Long> temp = set.subSet(lowerBound, upperBound);
 9             if (!temp.isEmpty()) {
10                 return true;
11             }
12             set.add((long)nums[i]);
13             if (set.size() > k) set.remove((long)nums[i-k]);
14             
15         }
16         return false;
17     }
18 }