using System;

using System.Collections.Generic;

public class Program

{

    public static void Main()

    {

        foreach (var i in sortKoffArrayWithHeap(new int[] { 1, 4, 5, 2, 3, 7, 8, 6, 10, 9 }, 2))

        {

            Console.Write(i + " ");

        }

        Console.WriteLine();

    }

    public static int[] sortKOffArray(int[] data, int k)

    {

        for (var i = 0; i < data.Length; i++)

        {

            var start = Math.Max(0, i - k);

            var end = Math.Min(data.Length, i + k);

​

            var num = data[i];

            if (start < i)

            {

                // switch left

                for (var j = i - 1; j >= start; j--)

                {

                    if (num < data[j])

                    {

                        var tmp = data[j];

                        data[j] = num;

                        data[j + 1] = tmp;

                    }

                }

            }

        }

        return data;

    }

    public static int[] sortKoffArrayWithHeap(int[] data, int k)

    {

        var heap = new SortedList<int, int> {};

        var result = new List<int> {};

        var maxHeapSize = 2 * k + 1;

        for (var i = 0; i < data.Length; i++)

        {

            heap.Add(data[i], data[i]);

            if (heap.Count > maxHeapSize)

            {

                var en = heap.GetEnumerator();

                en.MoveNext();

                result.Add(en.Current.Value);

                heap.RemoveAt(0);

            }

        }

        foreach(var val in heap)

        {

            result.Add(val.Value);

        }

        return result.ToArray();

    }

}