快速排序*^____^*

package Test01;

public class QuickSprt {

	public static void main(String[] args) {
		int[] arr = { 1, 3, 2, 9, 8, 7, 1, 0,0,2,3,3,1,0,101,100,1,1,001,100 }; // 要排序的数组
	

		QuickSort(arr);
		for (int i : arr) {
			System.out.print(i+"  ");
		}
	}

	public static void QuickSort(int[] arr) {
		if (arr == null || arr.length < 2) {
			return;
		} else {
			quickSort(arr, 0, arr.length - 1);
		}

	}

	public static void quickSort(int[] arr, int L, int R) {
		if (L < R) {
			int[] p = partition(arr, L, R);
			quickSort(arr, L, p[0] );
			quickSort(arr, p[1] , R);
		
		}
	}

	public static int[] partition(int[] arr, int L, int R) {
		int num = arr[(int) (Math .random()*(R-L+1)+L)];  //随机快排
		int less = L - 1;
		int more = R + 1;
		while (L < more) {
			if (arr[L] < num) {
				swap(arr, L++, ++less);

			} else if (arr[L] > num) {
				swap(arr, L, --more);

			} else {
				L++;
			}
		}
		return new int[] { less, more };

	}
	
	public static void swap(int arr[], int a, int b) {
		int temp = arr[a];
		arr[a] = arr[b];
		arr[b] = temp;

	}
}