1. Modify the BinarySearch program so that if the search key is in the array, it returns the largest index i for which a[i] is equal to key, but, otherwise, returns i where i is the largest index such that a[i] is less than key. It should also be modified to deal with integer arrays rather than string arrays.

Note: The program should take two command-line arguments, (1) an input file that contains a sorted integer array; and (2) an integer to search for in that array.

public class BinarySearch

{

public static int search(String key, String[] a)

{ return search(key, a 0, a.length); }

public static int search(String key, String[] a, int lo, int hi)

{ // Search for key in a[lo, hi).

if (hi <= lo) return -1;

int mid = lo + (hi - lo) / 2;

int cmp = a[mid].compareTo(key);

if (cmp > 0) return search(key, a, lo, mid);

else if (cmp < 0) return search(key, a, mid+1, hi);

else return mid;

}

publc static void main(String[] args)

{ // Print keys from the standard input that

// do not appear in file args[0].

In in = new In(args[0]);

String[] a= in.readAllStrings();

while (!StdIn.isEmpty())

{

String key = StdIn.readString();

if (search(key, a) < 0) StdOut.println(key);

}

}

}

Sample runs would be as follows. >more input.txt 2 3 4 5 6 6 6 7 8 9 11 >java BinarySearch input.txt 10 -9 >java BinarySearch input.txt 6 6