java实现各种排序算法

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主要实现了插入，冒泡，选择，归并，快速排序
代码如下：
package cn.com.cnn;//从小到大的顺序public class MySort {    public static void main(String[] args) {        int[] data = {3, 6, 4, 1, 5, 2};        MySort mySort = new MySort();        int[]  result1 = mySort.chooseSort(data);        for(int i : result1) {            System.out.print(i);        }        int[]  result2 = mySort.quickSort(data);        for(int i : result2) {            System.out.print(i);        }        int[]  result3 = mySort.insertSort(data);        for(int i : result3) {            System.out.print(i);        }        int[]  result4 = mySort.mergeSort(data);        for(int i : result4) {            System.out.print(i);        }        int[]  result5 = mySort.bubbleSort(data);        for(int i : result5) {            System.out.print(i);        }    }    //插入排序    public int[] insertSort(int[] data) {        for(int i = 1; i < data.length; i++) {            //0---j是现有的有序序列            int j = i - 1;            int temp = data[i];            while(j >= 0 && temp < data[j]) {                data[j + 1] = data[j];                j--;                    }            data[j + 1] = temp;        }        return data;    }    //冒泡排序    public int[] bubbleSort(int[] data) {        for(int i = 1; i < data.length; i++) {            for(int j = 0; j < data.length - i; j++) {                if(data[j] > data[j + 1]) {                    int temp = data[j];                    data[j] = data[j + 1];                    data[j + 1] = temp;                }            }        }        return data;    }    //选择排序    public int[] chooseSort(int[] data) {        for(int i = 0; i < data.length; i++) {            int minIndex = i;            for(int j = i + 1; j < data.length; j++) {                //找[i+1,length]中的最小值                if (data [j] < data[minIndex]) {                    minIndex = j;                }            }            int swap = data[i];            data[i] = data[minIndex];            data[minIndex] = swap;        }        return data;    }    //快速排序    public int[] quickSort(int[] data) {        int[] result = quickSortCore(data, 0, data.length - 1);        return result;    }    public int[] quickSortCore(int[] data, int leftIndex, int rightIndex) {        if(leftIndex >= rightIndex) {            return null;        }        int i = leftIndex;        int j =rightIndex;        int centerNum = data[leftIndex];        while(i < j) {            while(i < j && data[j] >= centerNum)                 j--;            data[i] = data[j];            while(i < j && data[i] <= centerNum)                i++;            data[j] = data[i];        }        data[j] = centerNum;        quickSortCore(data, leftIndex, j - 1);        quickSortCore(data, j + 1, rightIndex);        return data;    }    //归并排序    public int[] mergeSort(int data[]) {        int middIndex = (data.length - 1) / 2;        mergeSortCore(data, 0, middIndex);        mergeSortCore(data, middIndex + 1, data.length - 1);        merge(data, 0, middIndex, data.length - 1);        return data;    }    public int[] mergeSortCore(int data[], int leftIndex, int rightIndex) {        if(leftIndex < rightIndex) {            int middIndex = (leftIndex + rightIndex) / 2;            mergeSortCore(data, leftIndex, middIndex);            mergeSortCore(data, middIndex + 1, rightIndex);            merge(data, leftIndex, middIndex, rightIndex);        }        return data;    }    public int[] merge(int[] data, int leftIndex, int middIndex, int rightIndex) {        int[] tempArr = new int[rightIndex - leftIndex + 1];        int i = leftIndex;        int j = middIndex + 1;        int k = 0;        while(i <= middIndex && j <= rightIndex) {            if(data[i] < data[j]) {                tempArr[k++] = data[i++];            } else {                tempArr[k++] = data[j++];            }        }        //将剩余部分放回中间数组        while(i <= middIndex) {            tempArr[k++] = data[i++];        }        while(j <= rightIndex) {            tempArr[k++] = data[j++];        }        int m = 0;        while(leftIndex <= rightIndex) {            data[leftIndex++] = tempArr[m++];        }        return data;    }}
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