晕!!汗颜!java排序大集合

     强悍,想起上次东软笔试的一个程序设计题:排序,,极其简单,随便写一种就OK啦,可当时哎,,,惭愧,,竟乱七八糟写不好..,本想今晚来稍做汇总,,结果一搜,我倒!!!!

     转自:

[url]http://www.blogjava.net/javacap/archive/2007/12/13/167364.html[/url]

[url]http://www.blogjava.net/javacap/archive/2007/12/14/167618.html[/url]

     太强啦,得好好研究下哈,直接拷贝过来啦,,若真全他写的,太强啦,啥也不说啦.慢慢看吧:什么泛型,继承,抽象,-----有点太专业,啊!睡觉.下次在看,

    

/*
为了便于管理，先引入个基础类：
*/
package algorithms;

/**
* @author yovn
*
*/
public abstract class Sorter<E extends Comparable<E>> {
        
         public abstract void sort(E[] array, int from , int len);
        
         public final void sort(E[] array)
        {
                sort(array,0,array.length);
        }
         protected final void swap(E[] array, int from , int to)
        {
                E tmp=array[from];
                array[from]=array[to];
                array[to]=tmp;
        }

}
/*一 插入排序
该算法在数据规模小的时候十分高效，该算法每次插入第K+1到前K个有序数组中一个合适位置，K从0开始到N-1,从而完成排序：
*/
//
/**
* @author yovn
*/
public class InsertSorter<E extends Comparable<E>> extends Sorter<E> {

         /* (non-Javadoc)
         * @see algorithms.Sorter#sort(E[], int, int)
         */
         public void sort(E[] array, int from, int len) {
                 E tmp= null;
                     for( int i=from+1;i<from+len;i++)
                    {
                            tmp=array[i];
                             int j=i;
                             for(;j>from;j--)
                            {
                                     if(tmp.compareTo(array[j-1])<0)
                                    {
                                            array[j]=array[j-1];
                                    }
                                     else break;
                            }
                            array[j]=tmp;
                    }
        }
                
        

}
/*
二 冒泡排序
这可能是最简单的排序算法了，算法思想是每次从数组末端开始比较相邻两元素，把第i小的冒泡到数组的第i个位置。i从0一直到N-1从而完成排序。（当然也可以从数组开始端开始比较相邻两元素，把第i大的冒泡到数组的第N-i个位置。i从0一直到N-1从而完成排序。)

*/

/**
* @author yovn
*
*/
public class BubbleSorter<E extends Comparable<E>> extends Sorter<E> {

         private static     boolean DWON= true;
        
         public final void bubble_down(E[] array, int from, int len)
        {
                 for( int i=from;i<from+len;i++)
                {
                         for( int j=from+len-1;j>i;j--)
                        {
                                 if(array[j].compareTo(array[j-1])<0)
                                {
                                        swap(array,j-1,j);
                                }
                        }
                }
        }
        
         public final void bubble_up(E[] array, int from, int len)
        {
                 for( int i=from+len-1;i>=from;i--)
                {
                         for( int j=from;j<i;j++)
                        {
                                 if(array[j].compareTo(array[j+1])>0)
                                {
                                        swap(array,j,j+1);
                                }
                        }
                }
        }
        
         public void sort(E[] array, int from, int len) {
                
                 if(DWON)
                {
                        bubble_down(array,from,len);
                }
                 else
                {
                        bubble_up(array,from,len);
                }
        }
        
}
/*
三，选择排序
选择排序相对于冒泡来说，它不是每次发现逆序都交换，而是在找到全局第i小的时候记下该元素位置，最后跟第i个元素交换，从而保证数组最终的有序。
相对与插入排序来说，选择排序每次选出的都是全局第i小的，不会调整前i个元素了。
*/
/**
* @author yovn
*
*/
public class SelectSorter<E extends Comparable<E>> extends Sorter<E> {

         /* (non-Javadoc)
         * @see algorithms.Sorter#sort(E[], int, int)
         */
        @Override
         public void sort(E[] array, int from, int len) {
                 for( int i=0;i<len;i++)
                {
                         int smallest=i;
                         int j=i+from;
                         for(;j<from+len;j++)
                        {
                                 if(array[j].compareTo(array[smallest])<0)
                                {
                                        smallest=j;
                                }
                        }
                        swap(array,i,smallest);
                                        
                }

        }
    
}
/*
四 Shell排序
Shell排序可以理解为插入排序的变种，它充分利用了插入排序的两个特点：
1）当数据规模小的时候非常高效
2）当给定数据已经有序时的时间代价为O(N)
所以，Shell排序每次把数据分成若个小块，来使用插入排序，而且之后在这若个小块排好序的情况下把它们合成大一点的小块，继续使用插入排序，不停的合并小块，知道最后成一个块，并使用插入排序。

这里每次分成若干小块是通过“增量” 来控制的，开始时增量交大，接近N/2,从而使得分割出来接近N/2个小块，逐渐的减小“增量“最终到减小到1。

一直较好的增量序列是2^k-1,2^(k-1)-1,.....7,3,1,这样可使Shell排序时间复杂度达到O(N^1.5)
所以我在实现Shell排序的时候采用该增量序列
*/

/**
* @author yovn
*/
public class ShellSorter<E extends Comparable<E>> extends Sorter<E>    {

         /* (non-Javadoc)
         * Our delta value choose 2^k-1,2^(k-1)-1,.7,3,1.
         * complexity is O(n^1.5)
         * @see algorithms.Sorter#sort(E[], int, int)
         */
        @Override
         public void sort(E[] array, int from, int len) {
                
                 //1.calculate    the first delta value;
                 int value=1;
                 while((value+1)*2<len)
                {
                        value=(value+1)*2-1;
                
                }
        
                 for( int delta=value;delta>=1;delta=(delta+1)/2-1)
                {
                         for( int i=0;i<delta;i++)
                        {
                                modify_insert_sort(array,from+i,len-i,delta);
                        }
                }

        }
        
         private final     void modify_insert_sort(E[] array, int from, int len, int delta) {
                     if(len<=1) return;
                    E tmp= null;
                     for( int i=from+delta;i<from+len;i+=delta)
                    {
                            tmp=array[i];
                             int j=i;
                             for(;j>from;j-=delta)
                            {
                                     if(tmp.compareTo(array[j-delta])<0)
                                    {
                                            array[j]=array[j-delta];
                                    }
                                     else break;
                            }
                            array[j]=tmp;
                    }

        }
}
/*
五 快速排序
快速排序是目前使用可能最广泛的排序算法了。
一般分如下步骤：
1）选择一个枢纽元素（有很对选法，我的实现里采用去中间元素的简单方法）
2）使用该枢纽元素分割数组，使得比该元素小的元素在它的左边，比它大的在右边。并把枢纽元素放在合适的位置。
3）根据枢纽元素最后确定的位置，把数组分成三部分，左边的，右边的，枢纽元素自己，对左边的，右边的分别递归调用快速排序算法即可。
快速排序的核心在于分割算法，也可以说是最有技巧的部分。
*/
/**
* @author yovn
*
*/
public class QuickSorter<E extends Comparable<E>> extends Sorter<E> {

         /* (non-Javadoc)
         * @see algorithms.Sorter#sort(E[], int, int)
         */
        @Override
         public void sort(E[] array, int from, int len) {
                q_sort(array,from,from+len-1);
        }

        
         private final void q_sort(E[] array, int from, int to) {
                 if(to-from<1) return;
                 int pivot=selectPivot(array,from,to);

                
                
                pivot=partion(array,from,to,pivot);
                
                q_sort(array,from,pivot-1);
                q_sort(array,pivot+1,to);
                
        }


         private int partion(E[] array, int from, int to, int pivot) {
                E tmp=array[pivot];
                array[pivot]=array[to]; //now to's position is available
                
                 while(from!=to)
                {
                         while(from<to&&array[from].compareTo(tmp)<=0)from++;
                         if(from<to)
                        {
                                array[to]=array[from]; //now from's position is available
                                to--;
                        }
                         while(from<to&&array[to].compareTo(tmp)>=0)to--;
                         if(from<to)
                        {
                                array[from]=array[to]; //now to's position is available now    
                                from++;
                        }
                }
                array[from]=tmp;
                 return from;
        }


         private int selectPivot(E[] array, int from, int to) {
        
                 return (from+to)/2;
        }

}
/*
六 归并排序
算法思想是每次把待排序列分成两部分，分别对这两部分递归地用归并排序，完成后把这两个子部分合并成一个
序列。
归并排序借助一个全局性临时数组来方便对子序列的归并，该算法核心在于归并。
*/

import java.lang.reflect.Array;

/**
* @author yovn
*
*/
public class MergeSorter<E extends Comparable<E>> extends Sorter<E>    {

         /* (non-Javadoc)
         * @see algorithms.Sorter#sort(E[], int, int)
         */
        @SuppressWarnings( "unchecked")
        @Override
         public void sort(E[] array, int from, int len) {
                 if(len<=1) return;
                E[] temporary=(E[])Array.newInstance(array[0].getClass(),len);
                merge_sort(array,from,from+len-1,temporary);

        }

         private final void merge_sort(E[] array, int from, int to, E[] temporary) {
                 if(to<=from)
                {
                         return;
                }
                 int middle=(from+to)/2;
                merge_sort(array,from,middle,temporary);
                merge_sort(array,middle+1,to,temporary);
                merge(array,from,to,middle,temporary);
        }

         private final void merge(E[] array, int from, int to, int middle, E[] temporary) {
                 int k=0,leftIndex=0,rightIndex=to-from;
                System.arraycopy(array, from, temporary, 0, middle-from+1);
                 for( int i=0;i<to-middle;i++)
                {
                        temporary[to-from-i]=array[middle+i+1];
                }
                 while(k<to-from+1)
                {
                         if(temporary[leftIndex].compareTo(temporary[rightIndex])<0)
                        {
                                array[k+from]=temporary[leftIndex++];
                                
                        }
                         else
                        {
                                array[k+from]=temporary[rightIndex--];
                        }
                        k++;
                }
                
        }

}
/*七 堆排序
堆是一种完全二叉树，一般使用数组来实现。
堆主要有两种核心操作，
1）从指定节点向上调整(shiftUp)
2）从指定节点向下调整(shiftDown)
建堆，以及删除堆定节点使用shiftDwon,而在插入节点时一般结合两种操作一起使用。
堆排序借助最大值堆来实现，第i次从堆顶移除最大值放到数组的倒数第i个位置，然后shiftDown到倒数第i+1个位置,一共执行N此调整，即完成排序。
显然，堆排序也是一种选择性的排序，每次选择第i大的元素。
*/

/**
* @author yovn
*
*/
public class HeapSorter<E extends Comparable<E>> extends Sorter<E>    {

         /* (non-Javadoc)
         * @see algorithms.Sorter#sort(E[], int, int)
         */
        @Override
         public void sort(E[] array, int from, int len) {
                build_heap(array,from,len);

                 for( int i=0;i<len;i++)
                {
                         //swap max value to the (len-i)-th position
                        swap(array,from,from+len-1-i);
                        shift_down(array,from,len-1-i,0); //always shiftDown from 0
                }
        }

         private final void build_heap(E[] array, int from, int len) {
                 int pos=(len-1)/2; //we start from (len-1)/2, because branch's node +1=leaf's node, and all leaf node is already a heap
                 for( int i=pos;i>=0;i--)
                {
                        shift_down(array,from,len,i);
                }
                
        }
        
         private final void shift_down(E[] array, int from, int len, int pos)
        {
                
                E tmp=array[from+pos];
                 int index=pos*2+1; //use left child
                 while(index<len) //until no child
                {
                         if(index+1<len&&array[from+index].compareTo(array[from+index+1])<0) //right child is bigger
                        {
                                index+=1; //switch to right child
                        }
                         if(tmp.compareTo(array[from+index])<0)
                        {
                                array[from+pos]=array[from+index];
                                pos=index;
                                index=pos*2+1;
                                
                        }
                         else
                        {
                                 break;
                        }
                        
                }
                array[from+pos]=tmp;
                        
        }

        
}
/*
八 桶式排序
桶式排序不再是基于比较的了，它和基数排序同属于分配类的排序，这类排序的特点是事先要知道待排序列的一些特征。
桶式排序事先要知道待排序列在一个范围内，而且这个范围应该不是很大的。
比如知道待排序列在[0,M）内，那么可以分配M个桶，第I个桶记录I的出现情况，最后根据每个桶收到的位置信息把数据输出成有序的形式。
这里我们用两个临时性数组，一个用于记录位置信息，一个用于方便输出数据成有序方式，另外我们假设数据落在0到MAX,如果所给数据不是从0开始，你可以把每个数减去最小的数。
    
*/
/**
* @author yovn
*
*/
public class BucketSorter {

        
        
         public void sort( int[] keys, int from, int len, int max)
        {
                 int[] temp= new int[len];
                 int[] count= new int[max];
                
                
                 for( int i=0;i<len;i++)
                {
                        count[keys[from+i]]++;
                }
                 //calculate position info
                 for( int i=1;i<max;i++)
                {
                        count[i]=count[i]+count[i-1]; //this means how many number which is less or equals than i,thus it is also position + 1    
                }
                
                System.arraycopy(keys, from, temp, 0, len);
                 for( int k=len-1;k>=0;k--) //from the ending to beginning can keep the stability
                {
                        keys[--count[temp[k]]]=temp[k]; // position +1 =count
                }
        }
         /**
         * @param args
         */
         public static void main(String[] args) {

                 int[] a={1,4,8,3,2,9,5,0,7,6,9,10,9,13,14,15,11,12,17,16};
                BucketSorter sorter= new BucketSorter();
                sorter.sort(a,0,a.length,20); //actually is 18, but 20 will also work
                
                
                 for( int i=0;i<a.length;i++)
                {
                        System.out.print(a[i]+ ",");
                }

        }

}
/*
九 基数排序
基数排序可以说是扩展了的桶式排序，比如当待排序列在一个很大的范围内，比如0到999999内，那么用桶式排序是很浪费空间的。而基数排序把每个排序码拆成由d个排序码，比如任何一个6位数（不满六位前面补0）拆成6个排序码，分别是个位的，十位的，百位的。。。。
排序时，分6次完成，每次按第i个排序码来排。
一般有两种方式:
1) 高位优先(MSD)： 从高位到低位依次对序列排序
2）低位优先(LSD)： 从低位到高位依次对序列排序
计算机一般采用低位优先法（人类一般使用高位优先），但是采用低位优先时要确保排序算法的稳定性。
基数排序借助桶式排序，每次按第N位排序时，采用桶式排序。对于如何安排每次落入同一个桶中的数据有两种安排方法：
1）顺序存储：每次使用桶式排序，放入r个桶中，，相同时增加计数。
2）链式存储：每个桶通过一个静态队列来跟踪。

*/

import java.util.Arrays;


/**
* @author yovn
*
*/
public class RadixSorter {
        
         public static boolean USE_LINK= true;
        
         /**
         *    
         * @param keys
         * @param from
         * @param len
         * @param radix    key's radix
         * @param d            how many sub keys should one key divide to
         */
         public void sort( int[] keys, int from , int len, int radix, int d)
        {
                 if(USE_LINK)
                {
                        link_radix_sort(keys,from,len,radix,d);
                }
                 else
                {
                        array_radix_sort(keys,from,len,radix,d);
                }
                
        }
        
        
         private final void array_radix_sort( int[] keys, int from, int len, int radix,
                         int d)    
        {
                 int[] temporary= new int[len];
                 int[] count= new int[radix];
                 int R=1;
                
                 for( int i=0;i<d;i++)
                {
                        System.arraycopy(keys, from, temporary, 0, len);
                        Arrays.fill(count, 0);
                         for( int k=0;k<len;k++)
                        {
                                 int subkey=(temporary[k]/R)%radix;
                                count[subkey]++;
                        }
                         for( int j=1;j<radix;j++)
                        {
                                count[j]=count[j]+count[j-1];
                        }
                         for( int m=len-1;m>=0;m--)
                        {
                                 int subkey=(temporary[m]/R)%radix;
                                --count[subkey];
                                keys[from+count[subkey]]=temporary[m];
                        }
                        R*=radix;
                }
                        
        }


         private static class LinkQueue
        {
                 int head=-1;
                 int tail=-1;
        }
         private final void link_radix_sort( int[] keys, int from, int len, int radix, int d) {
                
                 int[] nexts= new int[len];
                
                LinkQueue[] queues= new LinkQueue[radix];
                 for( int i=0;i<radix;i++)
                {
                        queues[i]= new LinkQueue();
                }
                 for( int i=0;i<len-1;i++)
                {
                        nexts[i]=i+1;
                }
                nexts[len-1]=-1;
                
                 int first=0;
                 for( int i=0;i<d;i++)
                {
                        link_radix_sort_distribute(keys,from,len,radix,i,nexts,queues,first);
                        first=link_radix_sort_collect(keys,from,len,radix,i,nexts,queues);
                }
                 int[] tmps= new int[len];
                 int k=0;
                 while(first!=-1)
                {
                
                        tmps[k++]=keys[from+first];
                        first=nexts[first];
                }
                System.arraycopy(tmps, 0, keys, from, len);
                
                
        }
         private final void link_radix_sort_distribute( int[] keys, int from, int len,
                         int radix, int d, int[] nexts, LinkQueue[] queues, int first) {
                
                 for( int i=0;i<radix;i++)queues[i].head=queues[i].tail=-1;
                 while(first!=-1)
                {
                         int val=keys[from+first];
                         for( int j=0;j<d;j++)val/=radix;
                        val=val%radix;
                         if(queues[val].head==-1)
                        {
                                queues[val].head=first;
                        }
                         else    
                        {
                                nexts[queues[val].tail]=first;
                                
                        }
                        queues[val].tail=first;
                        first=nexts[first];
                }
                
        }
         private int link_radix_sort_collect( int[] keys, int from, int len,
                         int radix, int d, int[] nexts, LinkQueue[] queues) {
                 int first=0;
                 int last=0;
                 int fromQueue=0;
                 for(;(fromQueue<radix-1)&&(queues[fromQueue].head==-1);fromQueue++);
                first=queues[fromQueue].head;
                last=queues[fromQueue].tail;
                
                 while(fromQueue<radix-1&&queues[fromQueue].head!=-1)
                {
                        fromQueue+=1;
                         for(;(fromQueue<radix-1)&&(queues[fromQueue].head==-1);fromQueue++);
                        
                        nexts[last]=queues[fromQueue].head;
                        last=queues[fromQueue].tail;
                        
                }
                 if(last!=-1)nexts[last]=-1;
                 return first;
        }
        
         /**
         * @param args
         */
         public static void main(String[] args) {
                 int[] a={1,4,8,3,2,9,5,0,7,6,9,10,9,135,14,15,11,222222222,1111111111,12,17,45,16};
                USE_LINK= true;
                RadixSorter sorter= new RadixSorter();
                sorter.sort(a,0,a.length,10,10);
                 for( int i=0;i<a.length;i++)
                {
                        System.out.print(a[i]+ ",");
                }


        }

}