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