Java 簡單比較排序算法
序：一個愛上Java最初的想法一直沒有磨滅：”分享我的學習成果，不管後期技術有多深，打好基礎很重要“。
之前即將畢業那會兒，寫過關於排序算法的幾篇文章，有一些大學裏面學到的常見的算法，主要是因爲在應屆生面試的過程中，一些公司經常會問到學生一些這樣的問題，就想把它們分享出來，目的是希望給剛面臨找工作的Java初學者一些幫助，接下來我會貼出這些算法的源碼，同時歡迎去我的空間免積分下載，同是學習者，現在參加工作了，一直進，也想產出一點，希望給那些Java的愛好者，又在起跑線上的學者一些啓發作用，代碼並非最優的，歡迎同行指正。每一個算法源碼都有詳解，這裏面的源碼經過我後期的一些修改，因爲本人遇到了中文亂碼的問題，所以註釋用的是英文的，別以爲我英文有多好，要跨就誇有道去...
聲明：所有源碼經由本人原創，上道者皆似曾相識，另未經過權威機構或人士審覈和批准，勿做商業用途，僅供學習分享，若要轉載，請註明出處。
工具類Swapper，後期算法會使用這個工具類：
package com.meritit.sortord.comparison;
/**
* One util to swap tow element of Array
*
* @author ysjian
* @version 1.0
* @email [email protected]
* @QQ 646633781
* @telephone 18192235667
* @csdnBlog http://blog.csdn.net/ysjian_pingcx
* @createTime 2013-12-20
* @copyRight Merit
*/
public class Swapper {
private Swapper() {
}
/**
* Swap tow elements of the array
*
* @param oneIndex
* one index
* @param anotherIndex
* another index
* @param array
* the array to be swapped
* @exception NullPointerException
* if the array is null
*/
public static <T extends Comparable<T>> void swap(int oneIndex,
int anotherIndex, T[] array) {
if (array == null) {
throw new NullPointerException("null value input");
}
checkIndexs(oneIndex, anotherIndex, array.length);
T temp = array[oneIndex];
array[oneIndex] = array[anotherIndex];
array[anotherIndex] = temp;
}
/**
* Swap tow elements of the array
*
* @param oneIndex
* one index
* @param anotherIndex
* another index
* @param array
* the array to be swapped
* @exception NullPointerException
* if the array is null
*/
public static void swap(int oneIndex, int anotherIndex, int[] array) {
if (array == null) {
throw new NullPointerException("null value input");
}
checkIndexs(oneIndex, anotherIndex, array.length);
int temp = array[oneIndex];
array[oneIndex] = array[anotherIndex];
array[anotherIndex] = temp;
}
/**
* Check the index whether it is in the arrange
*
* @param oneIndex
* one index
* @param anotherIndex
* another index
* @param arrayLength
* the length of the Array
* @exception IllegalArgumentException
* if the index is out of the range
*/
private static void checkIndexs(int oneIndex, int anotherIndex,
int arrayLength) {
if (oneIndex < 0 || anotherIndex < 0 || oneIndex >= arrayLength
|| anotherIndex >= arrayLength) {
throw new IllegalArgumentException(
"illegalArguments for tow indexs [" + oneIndex + ","
+ oneIndex + "]");
}
}
}
ComparisonSortord:
package com.meritit.dm.csdn.sort.compare;
import com.meritit.dm.csdn.sort.Swapper;
/**
* Comparison sort order, time complexity is O(n2)
*
* @author ysjian
* @version 1.0
* @email [email protected]
* @QQ 646633781
* @telephone 18192235667
* @csdnBlog http://blog.csdn.net/ysjian_pingcx
* @createTime 2013-12-20
* @copyRight Merit
* @since 1.5
*/
public class ComparisonSortord {
private static final ComparisonSortord INSTANCE = new ComparisonSortord();
private ComparisonSortord() {
}
/**
* Get the instance of ComparisonSortord, only just one instance
*
* @return the only instance
*/
public static ComparisonSortord getInstance() {
return INSTANCE;
}
/**
* Sort the array of int with comparison sort order
*
* @param array
* the array of int
*/
public void doSort(int... array) {
if (array != null && array.length > 0) {
int length = array.length;
for (int i = 0; i < length - 1; i++) {
/*
* the current element of index i compares to any other elements
* after i
*/
for (int j = i + 1; j < length; j++) {
/*
* if the current element of index i is above the element,
* then swap them
*/
if (array[i] > array[j]) {
Swapper.swap(i, j, array);
}
}
}
}
}
/**
* Sort the array of generic <code>T</code> with comparison sort order
*
* @param array
* the array of generic
*/
public <T extends Comparable<T>> void doSortT(T[] array) {
if (array != null && array.length > 0) {
int length = array.length;
for (int i = 0; i < length - 1; i++) {
for (int j = i + 1; j < length; j++) {
if (array[i].compareTo(array[j]) > 0) {
Swapper.swap(i, j, array);
}
}
}
}
}
}
package com.meritit.dm.csdn.sort.compare;
import java.util.Arrays;
/**
* Test the comparison sort order
*
* @author ysjian
* @version 1.0
* @email [email protected]
* @QQ 646633781
* @telephone 18192235667
* @csdnBlog http://blog.csdn.net/ysjian_pingcx
* @createTime 2013-12-21
* @copyRight Merit
*/
public class TestComparisonSortord {
/**
* Test
*
* @param args
*/
public static void main(String[] args) {
ComparisonSortord compareSort = ComparisonSortord.getInstance();
int[] array = { 25, 35, 11, 45, 98, 65 };
System.out.println(Arrays.toString(array));
compareSort.doSort(array);
System.out.println(Arrays.toString(array));
System.out.println("------------------------");
Integer[] arrays = { 25, 35, 11, 45, 98, 65 };
System.out.println(Arrays.toString(arrays));
compareSort.doSortT(arrays);
System.out.println(Arrays.toString(arrays));
}
}