Java实现各种排序

package com.sbw.testredis;

import java.util.Arrays;


public class Sort{

    //冒泡排序 稳定 o(n^2)
    public void bubbleSort(int[] data){
        boolean isSort = true;
        for(int i = 0; i < data.length - 1 && isSort; i++){
            isSort = false;
            for(int j = data.length - 1; j > i; j--){
                if(data[j-1] > data[j]){
                    int temp = data[j-1];
                    data[j-1] = data[j];
                    data[j] =temp;
                    isSort = true;
                }
            }
        }

    }

    //选择排序 不稳定 o(n^2)
    public void chooseSort(int[] data){
        int min = 0;
        for(int i = 0; i < data.length - 1; i++){
            min = i;
            for(int j = i + 1; j < data.length; j++){
                if(data[j] < data[min]){
                    min = j;
                }
            }

            if(min != i){
                int temp = data[i];
                data[i] = data[min];
                data[min] = temp;
            }
        }
    }

    //插入排序 o(n^2) 稳定
    public void insertSort(int[] data){
        int i,j;
        for(i = 1; i < data.length; i++){
            if(data[i] < data[i-1]){
                int temp = data[i];
                for(j = i - 1; j >=0 && data[j] > temp; j--){
                    data[j+1] = data[j];
                }

                data[j+1] = temp;
            }
        }
    }

    //堆排序 从最后一个非叶子节点开始 不稳定 o(nlogn)
    public void heapSort(int[] data){
        int length = data.length;       
        for(int i = length/2 - 1; i >= 0; i--)
            buildMaxHeap(i, length, data);
        for(int i = length - 1; i > 0; i--){
            int temp = data[i];
            data[i] = data[0];
            data[0] = temp;

            buildMaxHeap(0, i, data);

        }
    }

    private void buildMaxHeap(int nodeIndex, int length, int[] data){
        int temp = data[nodeIndex];
        for(int i = 2 * nodeIndex + 1; i < length; i = 2 * i + 1){
            if(i < length - 1 && data[i] < data[i+1])
                i++;
            if(temp >= data[i])
                break;
            data[nodeIndex] = data[i];
            nodeIndex = i;
        }

        data[nodeIndex] = temp;

    }


    //快速排序 o(nlogn) o(logn) 不稳定
    public void quickSort(int[] data){
        _quickSort(data, 0, data.length - 1);       
    }

    private void _quickSort(int[] data, int left, int right){
        if(left < right){
            int middle = getMiddle(data, left, right);
            _quickSort(data, left, middle - 1);
            _quickSort(data, middle + 1, right);
        }
    }
    private int getMiddle(int[] data, int left, int right){
        int pivot = data[left];
        while(left < right){
            while(left < right && data[right] >= pivot)
                right--;        
            if (left < right)
                data[left++] = data[right];
            while (left < right && data[left] <= pivot)
                left++;
            if (left < right)
                data[right--] = data[left];
        }
        data[left] = pivot;
        return left;
    }

    //归并排序  o(nlogn) o(n) 稳定
    public void mergeSort(int[] arr){
        int[] temp =new int[arr.length];
        internalMergeSort(arr, temp, 0, arr.length-1);
    }
    private void internalMergeSort(int[] a, int[] b, int left, int right){
        if (left<right){
            int middle = (left+right)/2;
            internalMergeSort(a, b, left, middle);       
            internalMergeSort(a, b, middle+1, right);       
            mergeSortedArray(a, b, left, middle, right);    
        }
    }
    private void mergeSortedArray(int arr[], int temp[], int left, int middle, int right){
        int i=left;     
        int j=middle+1;
        int k=0;
        while (i <= middle && j <= right){
            if (arr[i] <= arr[j]){
                temp[k++] = arr[i++];
            }
            else{
                temp[k++] = arr[j++];
            }
        }
        while (i <= middle){
            temp[k++] = arr[i++];
        }
        while (j <= right){
            temp[k++] = arr[j++];
        }
        //把数据复制回原数组 
        for (i = 0; i < k; i++){
            arr[left+i] = temp[i];
        }
    }
    public static void main(String[] args){
        int[] data = {3,34,123,4,45,67,564,789,5,675};
        Sort test = new Sort();
        //test.bubbleSort(data);
        //test.chooseSort(data);
        //test.insertSort(data);
        //test.heapSort(data);  
        //test.quickSort(data);
        test.mergeSort(data);
        System.out.println(Arrays.toString(data));
    }
}