(Improve quick sort) The quick sort algorithm presented in the book selects the first element in the list as the pivot. Revise it by selecting the median among the first, middle, and last elements in the list

/*********************************************************************************
* (Improve quick sort) The quick sort algorithm presented in the book selects    *
* the first element in the list as the pivot. Revise it by selecting the median  *
* among the first, middle, and last elements in the list.                        *
*********************************************************************************/
public class Exercise_23_04 {
	public static void quickSort(int[] list) {
		quickSort(list, 0, list.length - 1);
	}

	public static void quickSort(int[] list, int first, int last) {
		if (last > first) {
			int pivotIndex = partition(list, first, last);
			quickSort(list, first, pivotIndex - 1);
			quickSort(list, pivotIndex + 1, last);
		}
	}

	/** Partition the aray list[first..last] */
	public static int partition(int[] list, int first, int last) {
		int middle = list[(list.length - 1) / 2];
		// choose the median element as the pivot
		int pivot = median(first, middle, last); 
		int low = first + 1; // Index for forward search
		int high = last; // Index for backward search

		while (high > low) {
			// Search forward from left
			while (low <= high && list[low] <= pivot)
				low++;

			// Search backward from right
			while (low <= high && list[high] > pivot)
				high--;

			// Swap two elements in the list
			if (high > low) {
				int temp = list[high];
				list[high] = list[low];
				list[low] = temp;
			}
		}

		while (high > first && list[high] >= pivot)
			high--;

		// Swap pivot with list[high]
		if (pivot > list[high]) {
			list[first] = list[high];
			list[high] = pivot;
			return high;
		}
		else {
			return first;
		}
	}

	/** A test method */
	public static void main(String[] args) {
		int[] list = {2, 3, 2, 5, 6, 1, -2, 3, 14, 12};
		quickSort(list);
		for (int i = 0; i < list.length; i++)
			System.out.print(list[i] + " ");
		System.out.println();
	}

	/** Returns the median of three integers */
	public static int median(int first, int middle, int last) {
		return Math.max(Math.min(first, middle), 
			Math.min(Math.max(first, middle), last));
	}
}