Java直接插入排序

Posted 2022-05-31 袁慎建@ThoughtWorks

Java直接插入排序 直接插入排序算法详解： http://blog.csdn.net/ysjian_pingcx/article/details/8674454 直接插入算法源码免积分下载： http://download.csdn.net/detail/ysjian_pingcx/6802851
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“。
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工具类Swapper，后期算法会使用这个工具类：

package com.meritit.sortord.util;

/**
 * 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 + "]");
		
	

直接插入排序，InsertionSortord：

package com.meritit.sortord.insertion;

/**
 * Insertion 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 2013-12-31
 * @copyRight Merit
 * @since 1.5
 */
public class InsertionSortord 

	private static final InsertionSortord INSTANCE = new InsertionSortord();

	private InsertionSortord() 
	

	/**
	 * Get the instance of InsertionSortord, only just one instance
	 * 
	 * @return the only instance
	 */
	public static InsertionSortord getInstance() 
		return INSTANCE;
	

	/**
	 * Sort the array of <code>int</code> with insertion sort order
	 * 
	 * @param array
	 *            the array of int
	 */
	public void doSort(int... array) 
		if (array != null && array.length > 0) 
			int length = array.length;

			// the circulation begin at 1,the value of index 0 is reference
			for (int i = 1; i < length; i++) 
				if (array[i] < array[i - 1]) 

					// if value at index i is lower than the value at index i-1
					int vacancy = i; // record the vacancy as i

					// set a sentry as the value at index i
					int sentry = array[i];

					// key circulation ,from index i-1 ,
					for (int j = i - 1; j >= 0; j--) 
						if (array[j] > sentry) 
							/*
							 * if the current index value exceeds the
							 * sentry,then move backwards, set record the new
							 * vacancy as j
							 */
							array[j + 1] = array[j];
							vacancy = j;
						
					
					// set the sentry to the new vacancy
					array[vacancy] = sentry;
				
			
		
	

	/**
	 * Sort the array of generic <code>T</code> with insertion 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 = 1; i < length; i++) 
				if (array[i].compareTo(array[i - 1]) < 0) 
					T sentry = array[i];
					int vacancy = i;
					for (int j = i - 1; j >= 0; j--) 
						if (array[j].compareTo(sentry) > 0) 
							array[j + 1] = array[j];
							vacancy = j;
						

					
					array[vacancy] = sentry;
				
			
		
	

测试TestInsertionSortord：

package com.meritit.sortord.insertion;

import java.util.Arrays;

/**
 * Test insertion sort order
 * 
 * @author ysjian
 * @version 1.0
 * @email [e-mail]
 * @QQ 646633781
 * @telephone [phone]
 * @csdnBlog http://blog.csdn.net/ysjian_pingcx
 * @createTime 2013-12-31
 * @copyRight Merit
 */
public class TestInsertionSortord 

	public static void main(String[] args) 
		InsertionSortord insertSort = InsertionSortord.getInstance();
		int[] array =  3, 5, 4, 2, 6 ;
		System.out.println(Arrays.toString(array));
		insertSort.doSort(array);
		System.out.println(Arrays.toString(array));
		System.out.println("---------------");
		Integer[] array1 =  3, 5, 4, 2, 6 ;
		System.out.println(Arrays.toString(array1));
		insertSort.doSortT(array1);
		System.out.println(Arrays.toString(array1));
	

直接插入排序算法详解： http://blog.csdn.net/ysjian_pingcx/article/details/8674454 直接插入算法源码免积分下载： http://download.csdn.net/detail/ysjian_pingcx/6802851