快排算法

 快排算法

// QuickSort implementation
        static void QuickSort (ArrayList szArray, int nLower, int nUpper)
        {
            // Check for non-base case
            if (nLower < nUpper)
            {
                // Split and sort partitions
                int nSplit = Partition (szArray, nLower, nUpper);
                QuickSort (szArray, nLower, nSplit - 1);
                QuickSort (szArray, nSplit + 1, nUpper);
            }
        }
        // QuickSort partition implementation
        static int Partition (ArrayList szArray, int nLower, int nUpper)
        {
            // Pivot with first element
            int nLeft = nLower + 1;
            string szPivot = (string) szArray[nLower];
            int nRight = nUpper;
            // Partition array elements
            string szSwap;
            while (nLeft <= nRight)
            {
                // Find item out of place
                while (nLeft <= nRight)
                {
                    if (((string) szArray[nLeft]).CompareTo (szPivot) > 0)
                        break;
                    nLeft = nLeft + 1;
                }
                while (nLeft <= nRight)
                {
                    if (((string) szArray[nRight]).CompareTo (szPivot) <= 0)
                        break;
                    nRight = nRight - 1;
                }
                // Swap values if necessary
                if (nLeft < nRight)
                {
                    szSwap = (string) szArray[nLeft];
                    szArray[nLeft] = szArray[nRight];
                    szArray[nRight] = szSwap;
                    nLeft = nLeft + 1;
                    nRight = nRight - 1;
                }
            }
            // Move pivot element
            szSwap = (string) szArray[nLower];
            szArray[nLower] = szArray[nRight];
            szArray[nRight] = szSwap;
            return nRight;
        }