14. Quicksort algo

//Write a program that sorts an array of strings
//using the quick sort algorithm (find it in Wikipedia).

using System;

    class QuickSortAlgo
    {
        static void Main()
        {
            Console.Write("Number of elemetns of the array: ");
            int n = int.Parse(Console.ReadLine());
            int[] array = new int[n];

            //populating the array
            for (int elements = 0; elements < array.Length; elements++)
            {
                Console.Write("Array 1, Element [{0}]: ", elements);
                int inputNumber = int.Parse(Console.ReadLine());
                array[elements] = inputNumber;
            }
            int startElement = 0;
            int endElement = n - 1;
            int[] secondaryArray = new int[n*2];

            //solve the task by declaring another array with double size than the first one,
            //and counting the positions on the left and on the right from the middle of the new array
            while (true)
            {
                int pivot = array[startElement];
                secondaryArray[secondaryArray.Length / 2] = array[startElement];
                int leftElementCounter = 0;
                int rightElementCounter = 0;
                for (int i = startElement + 1; i <= endElement; i++)
                {
                    if (pivot < array[i])
                    {
                        leftElementCounter++;
                        secondaryArray[n + leftElementCounter] = array[i];
                    }
                    else if (pivot > array[i])
                    {
                        rightElementCounter++;
                        secondaryArray[n - rightElementCounter] = array[i];
                    }
                }

                //transfer data to 1st array;
                int helper = 0;
                for (int i = startElement; i <= array.Length - 1; i++)
                {
                    array[i] = secondaryArray[n - rightElementCounter + helper];
                    helper++;
                }

                //check if the array is sorted.
                int checker = 0;
                for (int i = 0; i < array.Length - 1; i++)
                {
                    if (array[i] > array[i + 1])
                    {
                        startElement = i;
                        break;
                    }
                    else if (array[i] < array[i + 1])
                    {
                        checker++;
                    }
                }
                if (checker == n - 1)
                {
                    break;
                }

            }
            for (int i = 0; i < array.Length; i++)
            {
                Console.Write(array[i] + " ");
            }
            Console.WriteLine();

        }
    }