快速排序

import java.util.*;

public class QuickSort {

    public int[] quickSort(int[] A, int n) {

        int left = 0;

        int right = n-1;

        return quickSort(A, left, right);

    }

    public int[] quickSort(int[] A, int left, int right){

        if(left < right){

            int i = left;

            int j = right;

            int target = A[i];

            while(i < j){

                while(j>i && A[j]>target){

                    j--;

                }

                if(j>i){

                    A[i] = A[j];

                    i++;

                }

                while(i<j && A[i]<target){

                    i++;

                }

                if(i<j){

                    A[j] = A[i];

                    j--;

                }

            }

            A[i] = target;

            quickSort(A, left, i-1);

            quickSort(A, i+1, right);

        }

        return A;

    }

}