Bubble sort modifications

Instead of making nine comparisons on every pass, I need help modifing the bubble sort to make eight comparisons on the second pass, seven on the third pass and so on. Then I need it to check at the end of each pass whether any swaps have been made. If none have been made, the data must already be in the proper order, so the application should terminate. If swaps have been made, at least one more pass is needed. What do I need to add or change to my code to do these modifications?

namespace Enhanced_Bubble_Sort
{
    class Program
    {

        static void Main(string[] args)
        {
            int[] unsortedArray = new int[] { 23, 7, 10, 138, 2098, 2, 0, -5 };
            Console.WriteLine("UNSORTED");

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

            int[] sortedArray = BubbleSort(unsortedArray);
            Console.WriteLine("BUBBLE SORTED");
            for (int i = 0; i < sortedArray.Length; i++)
            {
                Console.WriteLine(sortedArray[i]);
            }
            Console.ReadLine();
        }

        private static int[] BubbleSort(int[] unsortedArray)
        {
            int length =unsortedArray.Length;
            for (int i = 0; i < length - 1; i++)
            {
                for (int j = 0; j < length - 1 - i; j++)
                {
                    if(unsortedArray[j] > unsortedArray[j + 1])
                    {
                        int num = unsortedArray[j];
                        unsortedArray[j] = unsortedArray[j + 1];
                        unsortedArray[j + 1] = num;
                    }
                }
            }
            return unsortedArray;

        }



    }
}

Tags: C#