Algs4-1.1.22以缩进方式打印递归参数

1.1.22使用1.1.64节中的rank()递归方法重新实现BinaraySearch并跟踪该方法的调用。每当该方法被调用时，打印出它的参数lo和hi并接照递归的深度缩进。提示：为递归方法添加一个参数来保存递归的深度。
import java.util.Arrays;
public class Test
{
    public static int rank(int key,int[] a)
    {
         StdOut.println("-----------------------");
        return rank(key,a,0,a.length-1,0);
       
    }
    public static int rank(int key,int[]a,int lo,int hi,int degree)
    {
       degree++;
       StdOut.printf("%-"+Integer.toString(2*degree)+"slo=%-4dhi=%-4d "," ",lo,hi);
       if(lo>hi) return -1;
       int mid=lo+(hi-lo)/2;
       if         (key<a[mid]) return rank(key,a,lo,mid-1,degree);
       else if  (key>a[mid]) return rank(key,a,mid+1,hi,degree);
       else                        return mid;
    }

    public static void main(String[] args)
    {
        int[] whitelist=In.readInts(args[0]);
        Arrays.sort(whitelist);
        while (!StdIn.isEmpty())
        {
            int key=StdIn.readInt();
            if (rank(key,whitelist)<0)
          StdOut.println(key);
         }  
    }
}