一、冒泡排序

package com.xwiam.algorithms.sort;

public class BubbleSort {

    private long[] instance;
    private int nElems;

    public BubbleSort(int maxSize) {
        instance = new long[maxSize];
        nElems = 0;
    }

    public void insert(long value) {
        instance[nElems] = value;
        nElems++;
    }

    public int find(long value) {
        for (int findPoint = 0;findPoint < nElems;findPoint++) {
            if (instance[findPoint] == value) {
                return findPoint;
            }
        }
        return nElems;
    }

    public boolean delete(long value) {
        int deletePoint = find(value);
        if (deletePoint == nElems) {
            return false;
        } else {
            for (int i = deletePoint; i < nElems - 1; i++) {
                instance[i] = instance[i + 1];
            }
            nElems--;
            return true;
        }
    }

    public void display() {
        for (int i = 0;i < nElems;i++) {
            System.out.print(instance[i] + " ");
        }
        System.out.println("");

    }

    public void sort() {
        for (int out = nElems - 1;out > 0;out--) {
            for (int in = 0;in < out;in++) {
                if (instance[in] > instance[in + 1]) {
                    swap(in, in + 1);
                }
            }
        }
    }

    private void swap(int source, int dest) {
        long temp = instance[source];
        instance[source] = instance[dest];
        instance[dest] = temp;
    }

    public static void main(String[] args) {
        BubbleSort bubbleSort = new BubbleSort(100);
        bubbleSort.insert(20);
        bubbleSort.insert(30);
        bubbleSort.insert(10);
        bubbleSort.display();
        bubbleSort.sort();
        bubbleSort.display();

    }
}

二、选择排序

package com.xwiam.algorithms.sort;

public class SelectSort {

    private long[] instance;
    private int nElems;

    public SelectSort(int maxSize) {
        instance = new long[maxSize];
        nElems = 0;
    }

    public void insert(long value) {
        instance[nElems] = value;
        nElems++;
    }

    public int find(long value) {
        for (int searchPoint = 0;searchPoint < nElems;searchPoint++) {
            if (instance[searchPoint] == value) {
                return searchPoint;
            }
        }
        return nElems;
    }

    public boolean delete(long value) {
        int deletePoint = find(value);
        if (deletePoint == nElems) {
            return false;
        } else {
            for (int i = deletePoint; i < nElems - 1; i++) {
                instance[i] = instance[i + 1];
            }
            nElems--;
            return true;
        }
    }

    public void display() {
        for (int i = 0;i < nElems;i++) {
            System.out.print(instance[i] + " ");
        }
        System.out.println("");
    }

    public void selectSort() {
        for (int out = 0;out < nElems - 1;out++) {
            int min = out;
            for (int in = out + 1;in < nElems;in++) {
                if (instance[in] < instance[min]) {
                    min = in;
                }
            }
            swap(out, min);
        }
    }

    private void swap(int source, int dest) {
        long temp = instance[source];
        instance[source] = instance[dest];
        instance[dest] = temp;
    }

    public static void main(String[] args) {
        SelectSort selectSort = new SelectSort(100);
        selectSort.insert(10);
        selectSort.insert(30);
        selectSort.insert(40);
        selectSort.insert(20);
        selectSort.display();
        selectSort.selectSort();
        selectSort.display();
    }
}

三、插入排序

package com.xwiam.algorithms.sort;

public class InsertSort {

    private long[] instance;
    private int nElems;

    public InsertSort(int maxSize) {
        instance = new long[maxSize];
        nElems = 0;
    }

    public void insert(long value) {
        instance[nElems] = value;
        nElems++;
    }

    public void display() {
        for (int i = 0;i < nElems;i++) {
            System.out.print(instance[i] + " ");
        }
        System.out.println("");
    }

    public void insertSort() {
        for (int out = 1;out < nElems;out++) {
            long temp = instance[out];
            int in = out;
            while (in > 0 && instance[in - 1] > temp){
                instance[in] = instance[in - 1];
                in--;
            }
            instance[in] = temp;
        }
    }

    public static void main(String[] args) {
        InsertSort insertSort = new InsertSort(100);
        insertSort.insert(10);
        insertSort.insert(30);
        insertSort.insert(40);
        insertSort.insert(20);
        insertSort.display();
        insertSort.insertSort();
        insertSort.display();

    }
}

四、三种简单排序算法的比较

冒泡排序做了N*(N-1)/2次比较，如果数据是随机的，交换的次数是N*(N-1)/4。（最坏的情况下，即初始数据逆序时，每次比较都需要交换）

选择排序做了N*(N-1)/2次比较，交换的次数<=N。当N值较小时，特别是如果交换的时间比比较的时间级大得多时，选择排序是相当快的。

插入排序 数据随机的话，做了N*(N-1)/4次比较，复制次数和比较次数大致相等，如果数据基本顺序排序的话，比较次数和复制次数只需要O(n) 的时间。