Leetcode 220 - remove duplicate III - using SortedSet GetViewBetween API

Leetcode220_removeDuplicateIII_SortedSet.cs

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Threading.Tasks;

namespace Leetcode220_ContainDuplicateIII
{
    /// <summary>
    /// Leetcode 220 - contains duplicate III
    /// https://leetcode.com/problems/contains-duplicate-iii/#/description
    /// </summary>
    class Leetcode220_ContainDuplicateIII
    {
        static void Main(string[] args)
        {
        }

        /// <summary>
        /// code review on June 29, 2017
        /// understand C# SortedSet GetViewBetween API
        /// </summary>
        /// <param name="nums"></param>
        /// <param name="k"></param>
        /// <param name="t"></param>
        /// <returns></returns>
        public bool ContainsNearbyAlmostDuplicate(int[] nums, int k, int t)
        {
            if (t < 0)
            {
                return false;
            }

            var binarySearchTree = new SortedSet<long>();
            for (int i = 0; i < nums.Length; i++)
            {
                var visit = (long)nums[i];

                if (binarySearchTree.GetViewBetween(visit - t, visit + t).Count > 0)
                {
                    return true;
                }

                binarySearchTree.Add(nums[i]);

                // remove node
                if (i >= k)
                {
                    // move the node out of tree by the range - k, one node a time
                    var nodeKStepAway = nums[i - k];

                    binarySearchTree.Remove(nodeKStepAway);
                }
            }

            return false;
        }
    }
}