SecondLab

using System;

namespace Labs
{
    class SecondLab
    {
        private int[] _arr = { 3, 2, 1, 0, 9, 7, 5, 3, 2, 4, 9, 5, 3, 3, 1, 0, 1, 3, 4, 4, 5, 7, 7, 9, 0 };
        private string _temp = "";
        private string _succession = "";
        private int i = 0, j = 1;

        public SecondLab()
        {
            Console.WriteLine("Your multitude is:\n");
            ArrPrint();
            Console.WriteLine("\n\n-----------------\n");
            Solu();
            Console.WriteLine("The longest succession is:\n\n" + _succession);
            Console.ReadKey();
        }

        private void Solu()
        {
            int len = _arr.Length;

            while (j < len - 1)
            {
                if (_arr[i] >= _arr[j])
                    goto Link;

                LessOrEqual();

                if (_arr[i] <= _arr[j])
                    continue;
            Link:
                GreaterOrEqual();
            }
        }

        private void LessOrEqual()
        {
            do
            {
                _temp += Convert.ToString(_arr[i]) + " ";
                
                if ((j == _arr.Length - 1) && (_arr[i] <= _arr[j]))
                {
                    _temp += Convert.ToString(_arr[j]);

                    if (_succession.Length <= _temp.Length)
                        _succession = _temp;

                    return;
                }
                i++;
                j++;
            }
            while (_arr[i] <= _arr[j]);

            _temp += Convert.ToString(_arr[i]);

            if (_succession.Length <= _temp.Length)
                _succession = _temp;

            _temp = "";
        }
        private void GreaterOrEqual()
        {
            do
            {
                _temp += Convert.ToString(_arr[i]) + " ";

                if ((j == _arr.Length - 1) && (_arr[i] >= _arr[j]))
                {
                    _temp += Convert.ToString(_arr[j]);

                    if (_succession.Length <= _temp.Length)
                        _succession = _temp;

                    return;
                }
                i++;
                j++;
            }
            while (_arr[i] >= _arr[j]);

            _temp += Convert.ToString(_arr[i]);

            if (_succession.Length <= _temp.Length)
                _succession = _temp;

            _temp = "";
        }

        private void ArrPrint()
        {
            foreach (int item in _arr)
                Console.Write(item + " ");
        }
    }
}