Middle_122_220_Contains Duplicate III.java

public class Solution {
  public boolean containsNearbyAlmostDuplicate(int[] nums, int k, int t) {
    if(k < 1 || t < 0)
      return false;
    TreeSet<Integer> set = new TreeSet<>();
    for(int i = 0; i < nums.length; i++){
      int n = nums[i];
      if(set.floor(n) != null && n <= t + set.floor(n) || 
          set.ceiling(n) != null && set.ceiling(n) <= t + n)
        return true;
      set.add(n);
      if (i >= k)
        set.remove(nums[i - k]);
    }
    return false;
  }
}