Java 比较排序算法

Posted 2022-05-31 袁慎建@ThoughtWorks

Java 简单比较排序算法
简单比较排序算法详解：        http://blog.csdn.net/ysjian_pingcx/article/details/8652091
简单比较排序算法源码下载： http://download.csdn.net/detail/ysjian_pingcx/6750815
序：一个爱上Java最初的想法一直没有磨灭：”分享我的学习成果，不管后期技术有多深，打好基础很重要“。                       之前即将毕业那会儿，写过关于排序算法的几篇文章，有一些大学里面学到的常见的算法，主要是因为在应届生面试的过程中，一些公司经常会问到学生一些这样的问题，就想把它们分享出来，目的是希望给刚面临找工作的Java初学者一些帮助，接下来我会贴出这些算法的源码，同时欢迎去我的空间免积分下载，同是学习者，现在参加工作了，一直进，也想产出一点，希望给那些Java的爱好者，又在起跑线上的学者一些启发作用，代码并非最优的，欢迎同行指正。每一个算法源码都有详解，这里面的源码经过我后期的一些修改，因为本人遇到了中文乱码的问题，所以注释用的是英文的，别以为我英文有多好，要跨就夸有道去...
声明：所有源码经由本人原创，上道者皆似曾相识，另未经过权威机构或人士审核和批准，勿做商业用途，仅供学习分享，若要转载，请注明出处。
工具类Swapper，后期算法会使用这个工具类：

package com.meritit.sortord.comparison;

/**
 * One util to swap tow element of Array
 * 
 * @author ysjian
 * @version 1.0
 * @email [e-mail]
 * @QQ 646633781
 * @telephone [phone]
 * @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 + "]");
		
	

下面是简单比较排序源码： 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 [e-mail]
 * @QQ 646633781
 * @telephone [phone]
 * @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);
					
				
			
		
	

测试TestComparisonSortord：

package com.meritit.dm.csdn.sort.compare;

import java.util.Arrays;

/**
 * Test the comparison sort order
 * 
 * @author ysjian
 * @version 1.0
 * @email [e-mail]
 * @QQ 646633781
 * @telephone [phone]
 * @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));
	

简单比较排序算法详解：        http://blog.csdn.net/ysjian_pingcx/article/details/8652091
简单比较排序算法源码下载： http://download.csdn.net/detail/ysjian_pingcx/6750815