package com.javasort.radixsorter;  
  
import java.util.Arrays;  
  
public class RadixSorter {  
public static boolean USE_LINK=true;  
      
    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;  
    }  
      
    public static void main(String[] args) {  
        int[] a={1,4,8,3,2,9,5,0,7,6,9,10,9,135,14,15,11,33,999999999,222222222,1111111111,12,17,45,16};  
        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]+",");  
        }  
  
  
    }