整理了几种常用的排序算法，留着自己看看

public class Sort {

	public static void main(String[] args) {
		int[] a = { 8, 7, 3, 5, 4, 2, 1, 6 };
		//bubbleSort2(a);
		//print(a);
		mineQuickSort(a, 0, a.length-1);
		display(a);
	}

	private static void display(int[] a) {
		for (int i = 0; i < a.length; i++) {
			System.out.print(a[i] + "  ");
		}
		System.out.println();
	}

	/**
	 * 直接插入排序
	 * 
	 * @param a
	 * @author  wyq
	 */
	public static void insertSort(int[] a) {
		int temp;
		int n = a.length;
		for (int i = 0; i < n - 1; i++) {
			temp = a[i + 1];
			int j = i;
			while (j > -1 && a[j] > temp) {
				a[j + 1] = a[j];
				j--;
			}
			a[j + 1] = temp;
		}
	}

	/**
	 * 直接选择排序
	 * 
	 * @param a
	 * @author  wyq
	 */
	public static void selectSort(int[] a) {
		int i, j, small;
		int temp;
		int n = a.length;
		for (i = 0; i < n; i++) {
			small = i;
			for (j = i + 1; j < n; j++)
				if (a[j] < a[small])
					small = j;

			if (small != i) {
				temp = a[i];
				a[i] = a[small];
				a[small] = temp;
			}
		}
	}

	/**
	 * 冒泡排序1
	 * 
	 * @param a
	 * @author  wyq
	 */
	public static void bubbleSort(int[] a) {
		int n = a.length;
		int temp;
		for (int i = 0; i < n; i++) {
			for (int j = n - 1; j > i; j--) {
				if (a[j] < a[j - 1]) {
					temp = a[j];
					a[j] = a[j - 1];
					a[j - 1] = temp;
				}
			}
		}
	}

	/**
	 * 冒泡排序2
	 * 
	 * @param a
	 * @author  wyq
	 */
	public static void bubbleSort2(int[] a) {
		int n = a.length;
		int temp, flag = 1;
		for (int i = 1; i < n && flag == 1; i++) {
			flag = 0;
			for (int j = 0; j < n - i; j++) {
				if (a[j] > a[j + 1]) {
					flag = 1;
					temp = a[j];
					a[j] = a[j + 1];
					a[j + 1] = temp;
				}
			}
		}
	}

	public static void quickSort(int[] a, int low, int high) {
		int i, j;
		int temp;
		i = low;
		j = high;
		temp = a[low];

		while (i < j) {
			// 在数组的右端扫描
			while (i < j && temp <= a[j]) j--;
			if (i < j) {
				a[i] = a[j];
				i++;
			}
			// 在数组的左端扫描
			while (i < j && a[i] < temp) i++;
			if (i < j) {
				a[j] = a[i];
				j--;
			}
		}
		a[i] = temp;
		
		if (low < i)
			quickSort(a, low, i - 1); // 对左端子集合递归
		if (i < high)
			quickSort(a, j + 1, high); // 对右端子集合递归
	}
	
	/**
	 * 
	 * @param a
	 * @param left
	 * @param right
	 * @return  中值
	 */
	public static int partition(int[] a, int left, int right) {
		int temp = a[left];
		
		while (left<right) {
			while (left<right && temp<a[right]) right --;
			a[left] = a[right];
			while (left<right && temp>a[left]) left++;
			a[right] = a[left];
		}
		a[left] = temp;
		
		return left;
	}
	
	/**
	 * 另一种快速排序
	 * @param a
	 * @param left
	 * @param right
	 */
	public static void mineQuickSort(int[] a, int left, int right) {
		if (left<right) {
			int middle = partition(a, left, right);
			mineQuickSort(a, left, middle-1);
			mineQuickSort(a, middle+1, right);
		}
	}
}

研究算法真是锻炼人的逻辑思维能力。