堆排序

package my_basic;

import java.util.Arrays;

public class HeapSort {
    
    public static void heapSort(int[] arr) {
        if (arr == null || arr.length <2) {
            return;
        }
        //建堆
        for (int i = 0; i < arr.length; i++) {
            heapInsert(arr,i);
        }
        int size = arr.length;
        swap(arr, 0, --size);
        
        /*调整堆*/
        while ( size > 0 ) {
            heapify(arr, 0, size);
            swap(arr, 0, --size);
        }
    }

    public static void heapInsert(int[] arr, int index) {
        while (arr[index] > arr[(index-1)/2]) {
            swap(arr,index,(index-1)/2);
            index = (index-1)/2;
        }
    }
    
    public static void swap(int[] arr, int i, int j) {
        int tmp = arr[i];
        arr[i] = arr[j];
        arr[j] = tmp;
        
    }
    /**
     * 调整堆
     * @param arr
     * @param index  要开始调整的位置
     * @param heapSize  标记越界
     */
    public static void heapify(int[] arr, int index, int heapSize) {
        int left = index * 2 + 1;
        while (left < heapSize) {
            int large = ((left+1) < heapSize && arr[left+1]>arr[left])
                    ? left+1
                    : left;
            large = arr[large] > arr[index] ? large : index;
            if (large == index) {
                break;
            }
            swap(arr, large, index);
            index = large;
            left = index * 2 + 1;
        }
    }
    
    public static int[] generateRandomArray(int maxSize, int maxValue) {
        int[] arr = new int[(int) ((maxSize+1) * Math.random())];
        for (int i = 0; i < arr.length; i++) {
            arr[i] = (int) ((maxValue+1) * Math.random() - (maxValue) * Math.random());
        }
        return arr;
    }
    public static int[] copyArray(int[] arr1) {
        int[] arr2 = new int[arr1.length];
        for (int i = 0; i < arr1.length; i++) {
            arr2[i] = arr1[i];
        }
        return arr2;
        
    }
    public static void comparator(int[] arr2) {
        Arrays.sort(arr2);
        
    }
    public static boolean isEqual(int[] arr1, int[] arr2) {
        if ((arr1==null && arr2!=null) || ((arr1!=null && arr2==null))) {
            return false;
        }
        if (arr1.length != arr2.length) {
            return false;
        }
        for (int i = 0; i < arr2.length; i++) {
            if (arr1[i] != arr2[i]) {
                return false;
            }
        }
        return true;
    }
    
    public static void main(String[] args) {
        int testTime = 500000;
        int maxSize = 100;
        int maxValue = 100;
        boolean succeed = true;
        for (int i = 0; i < testTime; i++) {
            int[] arr1 = generateRandomArray(maxSize, maxValue);
            int[] arr2 = copyArray(arr1);
            heapSort(arr1);
            comparator(arr2);
            if (!isEqual(arr1, arr2)) {
                succeed = false;
                break;
            }
        }
        System.out.println(succeed ? "Nice!" : "Fucking fucked!");

    }

}