Algs4-1.1.23区分在与不在白名单中的值

1.1.23为BinarySearch的测试用例添加一个参数：+打印出标准输入中不在白名单上的值;-，则打印出标准输入中在白名单上的值。
import java.util.Arrays;
public class Test
{
    public static int rank(int key,int[] a)
    {
          return rank(key,a,0,a.length-1);
    }
    public static int rank(int key,int[]a,int lo,int hi)
    {
       if(lo>hi) return -1;
       int mid=lo+(hi-lo)/2;
       if         (key<a[mid]) return rank(key,a,lo,mid-1);
       else if  (key>a[mid]) return rank(key,a,mid+1,hi);
       else                        return mid;
    }

    public static void main(String[] args)
    {
        int[] whitelist=In.readInts(args[0]);
        Arrays.sort(whitelist);
        StdOut.println("WhiteList--------------");
        for(int i=0;i<whitelist.length;i++)
            StdOut.println(whitelist[i]);
        StdOut.println("+not in whiteList,- in whiteList");
        while (!StdIn.isEmpty())
        {
            int key=StdIn.readInt();
            if (rank(key,whitelist)<0)
               StdOut.println("+"+key);
            else
                StdOut.println("-"+key);
         }  
    }
}