快速排序实现-JAVA

快速排序;

public class QuickSort {

public static void exchange(int [] arr, int i, int j)
{
    int temp;
    temp = arr[i];
    arr[i] = arr[j];
    arr[j] = temp;
}

public static void sort(int [] arr , int low , int high)
{
    int i,j,temp;
    i = low;
    j = high;
    
    if(i > j){
        return;
    }
    
    temp = arr[low];
    boolean flag = true;
    
    while( i < j ){
        if(flag){
            if(arr[j] < temp){
                exchange(arr, i, j);
                flag = false;
            }else{
                j --;
            }
        }else{
            if(arr[i] > temp){
                exchange(arr, i, j);
                flag = true;
            }else{
                i ++;
            }
        }
    }
    
    sort(arr,low,i-1);
    sort(arr,j+1,high);
}



public static void main(String[] args) {
    int [] arr = {1,2,6,3,7,8,1,9,1};
    sort(arr, 0, arr.length-1);
    
    for (int i : arr) {
        System.out.print(i+" ");
    }
}

}