快速排序

package com.cisco.www.test;

/**
 * 快排
 */
public class QuickSort1 {

    public static void quickSort(int[] arr){
        if(arr==null||arr.length<2){
            return;
        }
        quickSort(arr,0,arr.length-1);
    }
    //随机快排
    private static void quickSort(int[] arr, int l, int r) {
        if (l < r) {
            //将数组中随机位置上的元素和最后位置上的元素进行交换
            swap(arr, l + (int) (Math.random() * (r - l + 1)), r);
            int[] p = partition(arr, l, r);
            quickSort(arr, 0, p[0] - 1);
            quickSort(arr, p[1] + 1, r);
        }
    }

    //
    public static int[] partition(int[] arr, int l, int r) {
        int less = l-1;
        int more = r;
        while (l<more){
            if(arr[l]<arr[r]){
                swap(arr,++less,l++);
            }
            if(arr[l]>arr[r]){
                swap(arr,l,--more);
            }else {
                l++;
            }
        }
        swap(arr,more,r);
        return new int[]{less+1,more};
    }

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


    //test
    public static void main(String[] args){
        int testTime =1000000;
        int size =100;
        int value =100;
        boolean succeed =true;
        for(int i =0 ; i<testTime;i++){
            int[] arr1 = generateRandomArray(size,value);
            int[] arr2 = copyArray(arr1);
            if(!isEqual(arr1,arr2)){
                succeed=false;
                break;
            }
        }
        System.out.println(succeed?"Nice":"Fuck Fucked!");

        int[] arr = generateRandomArray(size,value);
        printArray(arr);
        quickSort(arr);
        printArray(arr);
    }

    private static void printArray(int[] arr) {
        if(arr==null){
            return;
        }
        for(int i = 0 ; i<arr.length;i++){
            System.out.print(arr[i]+" ");
        }
        System.out.println();
    }

    //test
    public static boolean isEqual(int[] arr1, int[] arr2) {
        if((arr1!=null&&arr2==null)||(arr1==null&&arr2!=null)){
            return false;
        }
        if(arr1==null&&arr2==null){
            return true;
        }
        if(arr1.length!=arr2.length){
            return false;
        }
        for(int i = 0 ; i <arr1.length;i++){
            if(arr1[i]!=arr2[i]){
                return false;
            }
        }
        return true;
    }

    //test
    public static int[] generateRandomArray(int size ,int value){
        int[] arr = new int[(int)(Math.random()*(size+1))];
        for(int i = 0 ; i<arr.length;i++){
            arr[i] = (int)(Math.random()*(size+1)) - (int)(Math.random()*(size));
        }
        return arr;
    }
    //test
    public static int[] copyArray(int[] arr){
        if(arr==null){
            return null;
        }
        int[] res = new int[arr.length];
        for(int i = 0 ; i <arr.length;i++){
            res[i] = arr[i];
        }
        return res;
    }
}