java_sort.java

java常用的排序算法源码

插入排序: 

package org.rut.util.algorithm.support; 

import org.rut.util.algorithm.SortUtil; 

public class InsertSort implements SortUtil.Sort{ 


public void sort(int[] data) { 
	int temp; 
	for(int i=1;i<data.length;i++){ 
		for(int j=i;(j>0)&&(data[j]<data[j-1]);j--){ 
			SortUtil.swap(data,j,j-1); 
		} 
	} 
} 


冒泡排序: 

package org.rut.util.algorithm.support; 

import org.rut.util.algorithm.SortUtil; 

public class BubbleSort implements SortUtil.Sort{ 


public void sort(int[] data) { 
	int temp; 
	for(int i=0;i<data.length;i++){ 
		for(int j=data.length-1;j>i;j--){ 
			if(data[j]<data[j-1]){ 
				SortUtil.swap(data,j,j-1); 
			} 
		} 
	} 
} 



选择排序: 

package org.rut.util.algorithm.support; 

import org.rut.util.algorithm.SortUtil; 


public class SelectionSort implements SortUtil.Sort { 


public void sort(int[] data) { 
	int temp; 
	for (int i = 0; i < data.length; i++) { 
		int lowIndex = i; 
		for (int j = data.length - 1; j > i; j--) { 
			if (data[j] < data[lowIndex]) { 
				lowIndex = j; 
			} 
		} 
		SortUtil.swap(data,i,lowIndex); 
	} 
} 

 

Shell排序: 

package org.rut.util.algorithm.support; 

import org.rut.util.algorithm.SortUtil; 


public class ShellSort implements SortUtil.Sort{ 


public void sort(int[] data) { 
	for(int i=data.length/2;i>2;i/=2){ 
		for(int j=0;j<i;j++){ 
			insertSort(data,j,i); 
		} 
	} 
	insertSort(data,0,1); 
} 


private void insertSort(int[] data, int start, int inc) { 
	int temp; 
	for(int i=start+inc;i<data.length;i+=inc){ 
		for(int j=i;(j>=inc)&&(data[j]<data[j-inc]);j-=inc){ 
			SortUtil.swap(data,j,j-inc); 
		} 
	} 
} 

 

快速排序: 

package org.rut.util.algorithm.support; 

import org.rut.util.algorithm.SortUtil; 


public class QuickSort implements SortUtil.Sort{ 


public void sort(int[] data) { 
	quickSort(data,0,data.length-1); 
} 

private void quickSort(int[] data,int i,int j){ 
	int pivotIndex=(i+j)/2; 

	SortUtil.swap(data,pivotIndex,j); 

	int k=partition(data,i-1,j,data[j]); 
	SortUtil.swap(data,k,j); 
	if((k-i)>1) quickSort(data,i,k-1); 
	if((j-k)>1) quickSort(data,k+1,j); 
} 

private int partition(int[] data, int l, int r,int pivot) { 
	do{ 
		while(data[++l]<pivot); 
		while((r!=0)&&data[--r]>pivot); 
		SortUtil.swap(data,l,r); 
	} 
	while(l<r); 
	SortUtil.swap(data,l,r); 
	return l; 
} 

 
改进后的快速排序: 

package org.rut.util.algorithm.support; 

import org.rut.util.algorithm.SortUtil; 

public class ImprovedQuickSort implements SortUtil.Sort { 

	private static int MAX_STACK_SIZE=4096; 
	private static int THRESHOLD=10; 

public void sort(int[] data) { 
	int[] stack=new int[MAX_STACK_SIZE]; 

	int top=-1; 
	int pivot; 
	int pivotIndex,l,r; 

	stack[++top]=0; 
	stack[++top]=data.length-1; 

	while(top>0){ 
		int j=stack[top--]; 
		int i=stack[top--]; 

		pivotIndex=(i+j)/2; 
		pivot=data[pivotIndex]; 

		SortUtil.swap(data,pivotIndex,j); 

//partition 
		l=i-1; 
		r=j; 
		do{ 
			while(data[++l]<pivot); 
			while((r!=0)&&(data[--r]>pivot)); 
			SortUtil.swap(data,l,r); 
		} 
		while(l<r); 
		SortUtil.swap(data,l,r); 
		SortUtil.swap(data,l,j); 

		if((l-i)>THRESHOLD){ 
			stack[++top]=i; 
			stack[++top]=l-1; 
		} 
		if((j-l)>THRESHOLD){ 
			stack[++top]=l+1; 
			stack[++top]=j; 
		} 

	} 
//new InsertSort().sort(data); 
	insertSort(data); 
} 

private void insertSort(int[] data) { 
	int temp; 
	for(int i=1;i<data.length;i++){ 
		for(int j=i;(j>0)&&(data[j]<data[j-1]);j--){ 
			SortUtil.swap(data,j,j-1); 
		} 
	} 
} 

 

归并排序: 

package org.rut.util.algorithm.support; 

import org.rut.util.algorithm.SortUtil; 

public class MergeSort implements SortUtil.Sort{ 

public void sort(int[] data) { 
	int[] temp=new int[data.length]; 
	mergeSort(data,temp,0,data.length-1); 
} 

private void mergeSort(int[] data,int[] temp,int l,int r){ 
	int mid=(l+r)/2; 
	if(l==r) return ; 
	mergeSort(data,temp,l,mid); 
	mergeSort(data,temp,mid+1,r); 
	for(int i=l;i<=r;i++){ 
		temp=data; 
	} 
	int i1=l; 
	int i2=mid+1; 
	for(int cur=l;cur<=r;cur++){ 
		if(i1==mid+1) 
			data[cur]=temp[i2++]; 
		else if(i2>r) 
			data[cur]=temp[i1++]; 
		else if(temp[i1]<temp[i2]) 
			data[cur]=temp[i1++]; 
		else 
			data[cur]=temp[i2++]; 
	} 
} 

 

改进后的归并排序: 

package org.rut.util.algorithm.support; 

import org.rut.util.algorithm.SortUtil; 

public class ImprovedMergeSort implements SortUtil.Sort { 

private static final int THRESHOLD = 10; 

public void sort(int[] data) { 
	int[] temp=new int[data.length]; 
	mergeSort(data,temp,0,data.length-1); 
} 

private void mergeSort(int[] data, int[] temp, int l, int r) { 
	int i, j, k; 
	int mid = (l + r) / 2; 
	if (l == r) 
	return; 
	if ((mid - l) >= THRESHOLD) 
		mergeSort(data, temp, l, mid); 
	else 
		insertSort(data, l, mid - l + 1); 
	if ((r - mid) > THRESHOLD) 
		mergeSort(data, temp, mid + 1, r); 
	else 
		insertSort(data, mid + 1, r - mid); 

	for (i = l; i <= mid; i++) { 
		temp = data; 
	} 
	for (j = 1; j <= r - mid; j++) { 
		temp[r - j + 1] = data[j + mid]; 
	} 
	int a = temp[l]; 
	int b = temp[r]; 
	for (i = l, j = r, k = l; k <= r; k++) { 
		if (a < b) { 
			data[k] = temp[i++]; 
			a = temp; 
		} else { 
			data[k] = temp[j--]; 
			b = temp[j]; 
		} 
	} 
}


private void insertSort(int[] data, int start, int len) { 
	for(int i=start+1;i<start+len;i++){ 
		for(int j=i;(j>start) && data[j]<data[j-1];j--){ 
			SortUtil.swap(data,j,j-1); 
		} 
	} 
} 

 
堆排序: 

package org.rut.util.algorithm.support; 

import org.rut.util.algorithm.SortUtil; 

public class HeapSort implements SortUtil.Sort{ 

public void sort(int[] data) { 
	MaxHeap h=new MaxHeap(); 
	h.init(data); 
	for(int i=0;i<data.length;i++) 
	h.remove(); 
	System.arraycopy(h.queue,1,data,0,data.length); 
} 


private static class MaxHeap{ 


	void init(int[] data){ 
		this.queue=new int[data.length+1]; 
		for(int i=0;i<data.length;i++){ 
			queue[++size]=data; 
			fixUp(size); 
		} 
} 

private int size=0; 

private int[] queue; 

public int get() { 
	return queue[1]; 
} 

public void remove() { 
	SortUtil.swap(queue,1,size--); 
	fixDown(1); 
} 
//fixdown 
private void fixDown(int k) { 
	int j; 
	while ((j = k << 1) <= size) { 
		if (j < size && queue[j]<queue[j+1]) 
			j++; 
		if (queue[k]>queue[j]) //不用交换 
		break; 
		SortUtil.swap(queue,j,k); 
		k = j; 
	} 
} 

private void fixUp(int k) { 
	while (k > 1) { 
		int j = k >> 1; 
		if (queue[j]>queue[k]) 
		break; 
		SortUtil.swap(queue,j,k); 
		k = j; 
	} 
} 

} 
 



SortUtil: 

package org.rut.util.algorithm; 

import org.rut.util.algorithm.support.BubbleSort; 
import org.rut.util.algorithm.support.HeapSort; 
import org.rut.util.algorithm.support.ImprovedMergeSort; 
import org.rut.util.algorithm.support.ImprovedQuickSort; 
import org.rut.util.algorithm.support.InsertSort; 
import org.rut.util.algorithm.support.MergeSort; 
import org.rut.util.algorithm.support.QuickSort; 
import org.rut.util.algorithm.support.SelectionSort; 
import org.rut.util.algorithm.support.ShellSort; 

public class SortUtil { 
public final static int INSERT = 1; 

public final static int BUBBLE = 2; 

public final static int SELECTION = 3; 

public final static int SHELL = 4; 

public final static int QUICK = 5; 

public final static int IMPROVED_QUICK = 6; 

public final static int MERGE = 7; 

public final static int IMPROVED_MERGE = 8; 

public final static int HEAP = 9; 

public static void sort(int[] data) { 
	sort(data, IMPROVED_QUICK); 
} 
private static String[] name={ 
	"insert","bubble","selection","shell","quick","improved_quick","merge", 
	"improved_merge","heap" 
}; 

private static Sort[] impl=new Sort[]{ 
new InsertSort(), 
new BubbleSort(), 
new SelectionSort(), 
new ShellSort(), 
new QuickSort(), 
new ImprovedQuickSort(), 
new MergeSort(), 
new ImprovedMergeSort(), 
new HeapSort() 
}; 

public static String toString(int algorithm){ 
	return name[algorithm-1]; 
} 

public static void sort(int[] data, int algorithm) { 
	impl[algorithm-1].sort(data); 
} 

public static interface Sort { 
	public void sort(int[] data); 
} 

public static void swap(int[] data, int i, int j) { 
	int temp = data; 
	data = data[j]; 
	data[j] = temp; 
}