java中的归并排序算法

public  static void merge(int[] array, int start, int mid, int end) 
    {
        int[] temp = new int[array.length];
        
        int i=start,j=mid+1,k=start;
        while(i != mid+1 && j != end +1 )
        {
            if(array[i] < array[j])
            {
                temp[k++] = array[i++];
            }
            else
            {
                temp[k++] = array[j++];
            }
        }
        while( i != mid + 1)
        {
            temp[k++] = array[i++];
        }
        while( j != end + 1)
        {
            temp[k++] = array[j++];
        }
        for(i = start;i<=end;i++)
        {
            array[i] = temp[i];
        }
        for(int p : array)
        {
            System.out.print( p + " ");
        }
        System.out.println();
    }
    
     static void mergeSort(int[] array, int start, int end) 
     {
         if(start < end)
         {
             int mid = (start + end) / 2;
             mergeSort(array,start,mid);
             mergeSort(array,mid+1,end);
             merge(array,start,mid,end);
         }
    }
    
    public static void main(String[] args) {
        int[] array = {100, 45, 47, 36, 21, 13, 7,0,123};
        //System.out.println(Arrays.toString(array));
        for(int i : array)
        {
            System.out.print( i + " ");
        }
        System.out.println();
        mergeSort(array,0,array.length-1);
    }