package 十大排序;

public class 快速排序 {
    
    

    public static void main(String[] args) {
    
    

        int[] arr = {
    
    6, 5, 4, 3, 2, 1};

        sort(arr, 0, arr.length-1);

        for (int i = 0; i < arr.length; i++) {
    
    
            System.out.print(arr[i] + " ");
        }

    }

    private static void sort(int[] arr, int p, int r) {
    
    
        if (p < r) {
    
    
            int q = partition(arr, p, r);
            sort(arr, p, q - 1);
            sort(arr, q + 1, r);
        }
    }


    public static int partition(int[] arr, int p, int r) {
    
    
        int pivot = arr[p];
        int sp = p +1;
        int big = r;
        while (sp <= big) {
    
    
            if (arr[sp] <= pivot) {
    
    
                sp++;
            } else {
    
    
                //交换
                int temp = arr[big];
                arr[big] = arr[sp];
                arr[sp] = temp;
                big--;
            }
        }
        //交换
        int temp = arr[big];
        arr[big] = pivot;
        arr[p] = temp;

        return big;
    }


}