保存一些常见的排序算法

import java.util.Arrays;
import java.util.Random;

public class Sort {
    public static void main(String[] args) {
        test();
//        sort();
    }

    private static void sort() {
        int[] nums = createArr(20, 200);
        print(nums);
        gnomeSort1(nums);
        print(nums);
    }

    private static void test() {
        long time1, time2;
        int[] ints;
        int length = 100000; //生成的数组长度
        int[] nums = createArr(length, Integer.MAX_VALUE);
        System.out.println(length + "长度数组排序测试");

        ints = Arrays.copyOf(nums, length);
        time1 = System.currentTimeMillis();
        selectionSort(ints);
        time2 = System.currentTimeMillis();
        System.out.println("选择排序耗时：" + (time2 - time1) + "ms");

        ints = Arrays.copyOf(nums, length);
        time1 = System.currentTimeMillis();
        bubbleSort(ints);
        time2 = System.currentTimeMillis();
        System.out.println("冒泡排序耗时：" + (time2 - time1) + "ms");

        ints = Arrays.copyOf(nums, length);
        time1 = System.currentTimeMillis();
        cockSort(ints);
        time2 = System.currentTimeMillis();
        System.out.println("鸡尾酒排序耗时：" + (time2 - time1) + "ms");

        ints = Arrays.copyOf(nums, length);
        time1 = System.currentTimeMillis();
        insertSort(ints);
        time2 = System.currentTimeMillis();
        System.out.println("插入排序耗时：" + (time2 - time1) + "ms");

        ints = Arrays.copyOf(nums, length);
        time1 = System.currentTimeMillis();
        shellSort(ints);
        time2 = System.currentTimeMillis();
        System.out.println("希尔排序耗时：" + (time2 - time1) + "ms");

        ints = Arrays.copyOf(nums, length);
        time1 = System.currentTimeMillis();
        heapSort(ints);
        time2 = System.currentTimeMillis();
        System.out.println("堆排序耗时：" + (time2 - time1) + "ms");

        ints = Arrays.copyOf(nums, length);
        time1 = System.currentTimeMillis();
        quickSort(ints, 0, ints.length - 1);
        time2 = System.currentTimeMillis();
        System.out.println("快速排序耗时：" + (time2 - time1) + "ms");

        ints = Arrays.copyOf(nums, length);
        time1 = System.currentTimeMillis();
        quickSort(ints, 0, ints.length - 1);
        time2 = System.currentTimeMillis();
        System.out.println("双轴快速排序耗时：" + (time2 - time1) + "ms");

        ints = Arrays.copyOf(nums, length);
        time1 = System.currentTimeMillis();
        mergeSort(ints, 0, ints.length - 1);
        time2 = System.currentTimeMillis();
        System.out.println("归并排序耗时：" + (time2 - time1) + "ms");

        ints = Arrays.copyOf(nums, length);
        time1 = System.currentTimeMillis();
        gnomeSort(ints);
        time2 = System.currentTimeMillis();
        System.out.println("地精排序耗时：" + (time2 - time1) + "ms");

        ints = Arrays.copyOf(nums, length);
        time1 = System.currentTimeMillis();
        gnomeSort1(ints);
        time2 = System.currentTimeMillis();
        System.out.println("地精排序优化版耗时：" + (time2 - time1) + "ms");

        ints = Arrays.copyOf(nums, length);
        time1 = System.currentTimeMillis();
        Arrays.sort(ints);
        time2 = System.currentTimeMillis();
        System.out.println("系统排序耗时：" + (time2 - time1) + "ms");

        ints = Arrays.copyOf(nums, length);
        time1 = System.currentTimeMillis();
        stoogeSort(ints, 0, ints.length - 1);
        time2 = System.currentTimeMillis();
        System.out.println("神经病排序耗时：" + (time2 - time1) + "ms");
    }

    //打印数组
    private static void print(int[] arr) {
        System.out.println(Arrays.toString(arr));
    }

    //生成随机数组
    public static int[] createArr(int length, int bounds) {
        int[] arr = new int[length];
        Random random = new Random();
        for (int i = 0; i < length; i++) {
            arr[i] = random.nextInt(bounds);
        }
        return arr;
    }

    //交换数组索引ij的数值
    private static void swap(int[] arr, int i, int j) {
        int temp = arr[j];
        arr[j] = arr[i];
        arr[i] = temp;
    }

    //选择排序
    public static void selectionSort(int[] arr) {
        int min;
        for (int i = 0; i < arr.length - 1; i++) {
            min = i;
            for (int j = i + 1; j < arr.length; j++) {
                if (arr[min] > arr[j]) {
                    min = j;
                }
            }
            swap(arr, i, min);
        }
    }

    //冒泡排序
    public static void bubbleSort(int[] arr) {
        for (int i = 0; i < arr.length - 1; i++) {
            for (int j = 0; j < arr.length - i - 1; j++) {
                if (arr[j] > arr[j + 1]) {
                    swap(arr, j, j + 1);
                }
            }
        }
    }

    //鸡尾酒冒泡
    public static void cockSort(int[] arr) {
        int min = 0, max = arr.length - 1;
        int index = 0;
        while (min < max) {
            for (int i = min; i < max; i++) {
                if (arr[i] > arr[i + 1]) {
                    swap(arr, i, i + 1);
                    index = i;
                }
            }
            max = index;
            for (int i = max; i > min; i--) {
                if (arr[i] < arr[i - 1]) {
                    swap(arr, i, i - 1);
                    index = i;
                }
            }
            min = index;
        }
    }

    //插入排序
    public static void insertSort(int[] arr) {
        int num, j;
        for (int i = 1; i < arr.length; i++) {
            num = arr[i];
            j = i - 1;
            while (j >= 0 && num < arr[j]) {
                arr[j + 1] = arr[j];
                j--;
            }
            arr[j + 1] = num;
        }
    }

    //希尔排序
    public static void shellSort(int[] arr) {
        int num, j, gap = arr.length / 2;
        while (gap >= 1) {
            for (int i = gap; i < arr.length; i++) {
                num = arr[i];
                j = i - gap;
                while (j >= 0 && num < arr[j]) {
                    arr[j + gap] = arr[j];
                    j -= gap;
                }
                arr[j + gap] = num;
            }
            gap >>>= 1;
        }
    }


    //神经病排序
    public static void stoogeSort(int[] arr, int i, int j) {
        int temp;
        if (arr[j] < arr[i]) {
            swap(arr, i, j);
        }
        if (j - i + 1 > 2) {
            temp = (j - i + 1) / 3;
            stoogeSort(arr, i, j - temp);
            stoogeSort(arr, i + temp, j);
            stoogeSort(arr, i, j - temp);
        }
    }

    //快速排序
    public static void quickSort(int[] arr, int left, int right) {
        if (left >= right) return;
        int i = left, j = right, temp = arr[left];
        while (i < j) {
            while (i < j && arr[j] >= temp) {
                j--;
            }
            while (i < j && arr[i] <= temp) {
                i++;
            }
            if (i < j) {
                swap(arr, i, j);
            }
        }
        arr[left] = arr[i];
        arr[i] = temp;
        quickSort(arr, left, i - 1);
        quickSort(arr, i + 1, right);
    }

    //双轴快排
    public static void QuickSortDualPivot(int[] A, int L, int R) {

        if (L >= R) {
            return;
        }

        if (A[L] > A[R]) {
            swap(A, L, R); //保证pivot1 <= pivot2
        }

        int pivot1 = A[L];
        int pivot2 = A[R];

        int i = L + 1;
        int k = L + 1;
        int j = R - 1;

        OUT_LOOP:
        while (k <= j) {
            if (A[k] < pivot1) {
                swap(A, i, k);
                k++;
                i++;
            } else if (A[k] >= pivot1 && A[k] <= pivot2) {
                k++;
            } else {
                while (A[j] > pivot2) {
                    j--;
                    if (j < k) {//当k和j错过
                        break OUT_LOOP;
                    }
                }
                if (A[j] >= pivot1 && A[j] <= pivot2) {
                    swap(A, k, j);
                    k++;
                    j--;
                } else {//A[j] < pivot1
                    swap(A, j, k);//注意k不动
                    j--;
                }
            }
        }
        i--;
        j++;
        swap(A, L, i);//将pivot1交换到适当位置
        swap(A, R, j);//将pivot2交换到适当位置

        //一次双轴切分至少确定两个元素的位置，这两个元素将整个数组区间分成三份
        QuickSortDualPivot(A, L, i - 1);
        QuickSortDualPivot(A, i + 1, j - 1);
        QuickSortDualPivot(A, j + 1, R);
    }

    //归并排序
    public static void mergeSort(int[] arr, int start, int end) {
        if (start >= end) return;
        int middle = (start + end) / 2;
        mergeSort(arr, start, middle);
        mergeSort(arr, middle + 1, end);
        merge(arr, start, middle, end);
    }

    private static void merge(int[] array, int start, int middle, int end) {
        int[] aux = new int[end - start + 1];
        System.arraycopy(array, start, aux, 0, end - start + 1);
        int left = start;
        int right = middle + 1;
        for (int k = start; k <= end; k++) {
            if (left > middle) {
                array[k] = aux[right - start];
                right++;
            } else if (right > end) {
                array[k] = aux[left - start];
                left++;
            } else if (aux[left - start] > aux[right - start]) {
                array[k] = aux[right - start];
                right++;
            } else {
                array[k] = aux[left - start];
                left++;
            }
        }
    }

    //堆排序
    public static void heapSort(int[] arr) {
        int len = arr.length - 1;
        //生成大顶堆
        for (int parent = len / 2 - 1; parent >= 0; parent--) {
            heapAdjust(arr, parent, len);
        }
        //每次截取大顶堆的根结点，排在数组最后，然后调整剩下的堆使其保持大顶堆
        while (len >= 0) {
            swap(arr, 0, len--);
            heapAdjust(arr, 0, len);
        }
    }

    //从parent节点开始调整堆保持parent它的子节点为大顶堆
    private static void heapAdjust(int[] arr, int parent, int len) {
        int leftChild, rightChild, maxChild;
        while ((leftChild = parent * 2 + 1) <= len) {
            rightChild = leftChild + 1;
            maxChild = leftChild;
            if (maxChild < len && (arr[leftChild] < arr[rightChild])) {
                maxChild++;
            }
            if (arr[parent] < arr[maxChild]) {
                swap(arr, parent, maxChild);
                parent = maxChild;
            } else {
                break;
            }
        }
    }

    //地精排序
    public static void gnomeSort(int[] arr) {
        for (int i = 0; i < arr.length; ) {
            if (i == 0 || arr[i - 1] <= arr[i]) i++;
            else swap(arr, i, --i);
        }
    }

    //地精排序优化版1
    public static void gnomeSort1(int[] arr) {
        for (int i = 0, p = 0; i < arr.length; ) {
            if (i == 0 || arr[i - 1] <= arr[i]) i = ++p;
            else swap(arr, i, --i);
        }
    }
}