import java.util.Arrays;

 public class MergeSort {

     public static void main(String[] args) {

         MergeSort ms=new MergeSort();

         int[] arr={5,44,32,4,566,67,23};

         ms.merge(arr, 0, arr.length-1);

         System.out.println(Arrays.toString(arr));

     }

     void merge(int[] arr,int start,int end )

     {

         if(start==end)

             return ;

         int mid=(start+end)/2;

         merge(arr,start,mid);//左边排序递归

         merge(arr,mid+1,end);//you边排序递归

         combine(arr,start,mid,end);

     }

     void combine(int[] arr,int start,int mid,int end) {

         int length=end-start+1;

         int tempArr[]=new int[length];

         int tempIndex=0;

         int left=start;

         int right=mid+1;

         while(left<=mid&&right<=end)

         {

             if(arr[left]<arr[right])

                 tempArr[tempIndex++]=arr[left++];

             else

                 tempArr[tempIndex++]=arr[right++];

         }

         while(left<=mid)

             tempArr[tempIndex++]=arr[left++];

         while(right<=end)

             tempArr[tempIndex++]=arr[right++];

         for(int i=0;i<tempArr.length;i++)

         {

             arr[start+i]=tempArr[i];

         }

     }

 }