/**
 * A class to demonstrate recursive binary search
 **/
public class BinrySearch
{
    /**
     * Class variable holding the data to be serched
     **/
    private int[] data;

    public BinrySearch()
    {
	this(10);
    }

   /**
     * Initialize the search with n numbers
     * @param n the number of numbers to be searched
     */
    public BinrySearch(int n)
    {
	data = new int[n];
	for (int i=0; i<n; i++) data[i]=i*2;
    }
    
    /**
     * Public method for binary search
     * This hides the internal implementation as it accepts only the number to be serched for
     * @param target the number to search for
     * @return true if the number is in the list
     **/ 
    public boolean search(int target)
    {
	return iSearch(target, 0, data.length-1, 1);
    }
    /**
     * Implement Binary search, recursively on internal array of ints
     * @param target the item to be found
     * @param lo the bottom of the range being searched
     * @param hi the top of the range being searched
     * @param steps the number of steps the search has taken
     * @return true if the target was found
     */
    private boolean iSearch(int target, int lo, int hi, int steps)
    {
	if (lo>hi) return false;
	int mid = (lo+hi)/2;
	System.out.println(target + " " + data[mid] + " " + lo + " " + hi + " " + steps);
	if (data[mid]==target) return true;
	if (data[mid]<target)
	    return iSearch(target, mid+1, hi, steps+1);
	else
	    return iSearch(target, lo, mid-1, steps+1);
    }

    
    public static void main(String[] args)
    {
	BinrySearch bs = new BinrySearch(2048);
	int[] tgts = {512, 2174, 12, 23};
	for (int ii : tgts)
	    System.out.println(bs.search(ii) ? "Found" : "Not Found");
    }
}