幾種排序的java實作：選擇、插入、冒泡、快排

import java.io.*;

import java.util.*;

public class mySort {

double[] arrayToSort = null;

public mySort(){

ArrayList<String> temp = new ArrayList<String>();

InputStreamReader stdin = new InputStreamReader(System.in); 

BufferedReader br = new BufferedReader(stdin);

String readin = null;

System.out.println("please input the numbers to be sorted \n");

do{

try{

readin = br.readLine();

}catch(Exception e){

e.printStackTrace();

}

String[] tempStr = readin.split(" ");

for(int i = 0; i < tempStr.length; i++){

temp.add(tempStr[i]);

}

}while(!readin.isEmpty());

arrayToSort = new double[temp.size() - 1];

int i = 0;

Iterator<String> it = temp.iterator();

while(it.hasNext() && i != temp.size()-1){

arrayToSort[i++] = Double.parseDouble(it.next());

}

}

public void selectSort(){

double max = 0;

int maxloc = 0;

for(int i = 0; i < arrayToSort.length; i++){

max = arrayToSort[i];

maxloc = i;

for(int j = i + 1; j <arrayToSort.length; j++){

if(arrayToSort[j] >  max){

max = arrayToSort[j];

maxloc = j;

}

}

if(maxloc != i){

double temp = arrayToSort[i];

arrayToSort[i] = arrayToSort[maxloc];

arrayToSort[maxloc] = temp;

}

}

}

public void insertSort(){

for(int i = arrayToSort.length - 1; i > 0; i--){

if(arrayToSort[i] > arrayToSort[i - 1]){

mySort.exchange(arrayToSort, i, i - 1);

}

}

for(int i = 1; i < arrayToSort.length; i++){

double v = arrayToSort[i]; int j = i;

while(arrayToSort[j] > arrayToSort[j - 1]){

mySort.exchange(arrayToSort, j, j - 1);

j--;

}

arrayToSort[j] = v;

}

}

public void bubbleSort(){

for(int i = arrayToSort.length - 1; i > 0; i--){

int key = 0;

for(int j = 1; j <= i; j++){

if(arrayToSort[j] > arrayToSort[j - 1]){

mySort.exchange(arrayToSort, j, j - 1);

key = 1;

}

}

if(key == 0)

break;

}

}

public void qSort(){

qSortFunc(arrayToSort,0,arrayToSort.length - 1);

}

public void qSortFunc(double[] a, int l, int r){

if(l >= r) return;

int p = partition(a,l,r);

qSortFunc(a,l,p - 1);

qSortFunc(a,p + 1,r);

}

public int partition(double[] a, int l, int r){

int i = l + 1; int j = r; double key = a[l];

while(true){

while(a[j] < key)j--;

while(a[i] > key){

i ++;

if(i >= r){

break;

}

}

if(i >= j){

mySort.exchange(a, j, l);

break;

}

mySort.exchange(a, i, j);

i++;

j--;

}

System.out.print("left:  ");

mySort.show(arrayToSort, l, j);

System.out.print("right:  ");

mySort.show(arrayToSort, j, r);

return j;

}

public static void exchange(double[] a, int i ,int j){

double temp = a[i];

a[i] = a[j];

a[j] = temp;

}

public static void show(double[] a, int i, int j){

for(;i<=j;i++){

System.out.print(a[i] + " ");

}

System.out.println("\n");

}

public static void main(String[] args){

mySort test = new mySort();

test.qSort();

for(double i : test.arrayToSort){

System.out.print(i + " ");

}

}

}