[C# basic] Pr6. * Longest Non-Decreasing Sequence

using System;
using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
/*Problem 6.    * Longest Non-Decreasing Sequence
Write a program that reads a sequence of integers and finds in it the longest non-decreasing subsequence. In other words, you should remove a minimal number of numbers from the starting sequence, so that the resulting sequence is non-decreasing. In case of several longest non-decreasing sequences, print the leftmost of them. The input and output should consist of a single line, holding integer numbers separated by a space.
*/
/*https://www.youtube.com/watch?v=Sk0PX0YSHtk */
class Program
{
    static void Main()
    {
        string numberStr = Console.ReadLine();// enter numers on one line separated by space
        char[] split = new char[] { ' ', ',', ';' };//split by
        string[] spliedNum = numberStr.Split(split, StringSplitOptions.RemoveEmptyEntries);
        int[] numbers = new int[spliedNum.Length];
        int n = numbers.Length;// how many numbers we have
        for (int i = 0; i < n; i++)
        {
            if (int.TryParse(spliedNum[i], out numbers[i])) numbers[i] = int.Parse(spliedNum[i]);
        }
        List<int> numberSeq = new List<int>();
        List<int> numberSeqMax = new List<int>();
        int maxI = (int)Math.Pow((double)2, n) - 1; // number of combination needed to generate  using number as binary
        for (int i = maxI; i >= 1; i--)// no need to check for zeroes start from last to first fo first true and stop
        {// combination of numbers we will take or not
            string numBinStr = Convert.ToString(i, 2).PadLeft(n, '0');// generate combination
            for (int bit = 0; bit < numBinStr.Length; bit++)
            {// generate unique List of sequnece combination
                if (numBinStr[bit] == '1')
                {
                    numberSeq.Add(numbers[bit]);
                }
            }
            bool isNonDecr = true;
            List<int> countEncr = new List<int>();
            List<int> countEqual = new List<int>();
            for (int y = 0; y < numberSeq.Count - 1; y++)
            { // serch for Encreasing
                if (numberSeq[y] > numberSeq[y + 1])
                {// check and skip search for increasing/ equals
                    isNonDecr = false;
                }
            }
            if (isNonDecr)
            {
                for (int y = 0; y < numberSeq.Count - 1; y++)
                { // serch for equal
                    if (numberSeq[y] == numberSeq[y + 1])
                    {//1 1 1 2 2 2 - > 1 1 1 or 4 1 4 2 4 3 4 - > 4 4 4 4
                        countEqual.Add(numberSeq[y]);
                        if (y == numberSeq.Count - 2)// chech before before the last // this if stay inside
                        {// add last elm
                            countEqual.Add(numberSeq[y + 1]);
                        }
                    }
                    else break;
                }
                for (int y = 0; y < numberSeq.Count - 1; y++)
                { // serch for Encreasing
                    if (numberSeq[y] < numberSeq[y + 1])
                    { // 4 1 1 2  - > 1 2
                        countEncr.Add(numberSeq[y]);
                        if (y == numberSeq.Count - 2)// chech before before the last // this if stay inside
                        {// add last elm
                            countEncr.Add(numberSeq[y + 1]);
                        }
                    }
                    else break;
                }
            }

            if (isNonDecr && countEncr.Count > numberSeqMax.Count)
            {// add countEncr // 4 1 1 2  - > 1 2
                numberSeqMax.Clear();
                numberSeqMax = countEncr.ToList();
                numberSeq.Clear();
                countEncr.Clear();
            }
            else if (isNonDecr && countEqual.Count > numberSeqMax.Count)
            {//add countEqual //1 1 1 2 2 2 - > 1 1 1 /// 1 4 1  2 1  - > 1 1 1
                numberSeqMax.Clear();
                numberSeqMax = countEqual.ToList();
                numberSeq.Clear();
                countEqual.Clear();
            }
            else numberSeq.Clear();//clear sequence
        }
        foreach (var item in numberSeqMax)
        {
            Console.WriteLine(item);
        }
    }
}