合并排序 java

         java  实现合并排序

package How;

import java.io.BufferedReader;
import java.io.BufferedWriter;
import java.io.FileReader;
import java.io.FileWriter;
import java.io.IOException;
import java.lang.reflect.Array;
import java.util.Random;

import org.omg.PortableInterceptor.DISCARDING;

public class bin_1 
{
    public static void main(String[] args) 
    {
        try 
        {
            mergesortSort myMergesortSort=new mergesortSort();
            myMergesortSort.display();
        } catch (IOException e) 
        {
            // TODO Auto-generated catch block
            e.printStackTrace();
        }
    }
}
class mergesortSort
{
    int size=6;
    int []array;
    int []temp;
    BufferedWriter fout_1;
    BufferedWriter fout_2;
    //准备数据
    public mergesortSort() throws IOException
    {
        fout_1=new BufferedWriter(new FileWriter("noOrder.txt"));
        fout_2=new BufferedWriter(new FileWriter("inOrder.txt"));
        Random random=new Random();
        array=new int[size];
        this.temp=new int[size];
        for(int i=0; i<size; i++)
        {
            array[i]=random.nextInt(100);
            fout_1.write(array[i]+"");
            fout_1.newLine();
        }
        fout_1.flush();
        mergesort( 0,  size-1);
    }
    //方便调用
    public mergesortSort(int []array, int l, int r ) throws IOException
    {
        fout_1=new BufferedWriter(new FileWriter("noOrder.txt"));
        fout_2=new BufferedWriter(new FileWriter("inOrder.txt"));
        this.array=array;
        this.temp=new int[l-r+1];
        mergesort( l,  r);
    }
    public mergesortSort(int []array) throws IOException
    {
        fout_1=new BufferedWriter(new FileWriter("noOrder.txt"));
        fout_2=new BufferedWriter(new FileWriter("inOrder.txt"));
        this.array=array;
        this.temp=new int[array.length];
        mergesort( 0,  array.length-1);
    }
    public void mergesort(int l, int r)
    {
        if(l<r)
        {
            int m=(l+r)/2;
            mergesort( l, m);
            mergesort( m+1, r);
            merge( l,  m,  r);
        }
    }
    public void merge(int l, int m, int r)
    {
        int p=l;       
        int q=m+1;
        int k=0;
        System.out.println("p="+p);
        System.out.println("q="+q);
        while(p<=m&&r>=q)  
        {
            if(array[p]<=array[q]) //谁小谁先进
            {
                temp[k++]=array[p];
                p++;
            }
            else
            {
                temp[k++]=array[q];
                q++;
            }
            System.out.println(""+array[k]);
        }
        if(p<=m)
        {
            for(int i=p; i<=m;  i++)
            {
                temp[k++]=array[i];
            }
        }
        else
        {
            for(int i=q; i<=r;  i++)
            {
                temp[k++]=array[i];
            }
        }
        //复制  这里比较容易出错
        for(int i=0; i<k; i++)
        {
            array[l++]=temp[i];
        }
    }
    public  void display() throws IOException
    {
        
        for(int i=0; i<array.length; i++)
        {
            fout_2.write(""+array[i]);
            fout_2.newLine();
        }
        fout_2.flush();
    }
}

         运行结果