Binary Search

import java.util.Scanner;

/**
*Program to perform Binary Search
*@author Steve Robinson
*@see footyntech.wordpress.com
*/

class BinarySearch
{
    public static void main(String arg[])
    {
        Scanner in=new Scanner(System.in);
        int key,loc;
        char ch;

        System.out.print("Enter the number of elements of the List: ");
        int len=in.nextInt();
        int[]array=new int[len];

        System.out.println("Enter the elements in \"ascending order only\"....");
        for(int i=0;i<len;i++)
        {
            System.out.println("Element "+(i+1)+": ");
            array[i]=in.nextInt();
        }
        do
        {
            System.out.print("Enter the element to search for: ");
            key=in.nextInt();
            loc=binarySearch(array,key,0,len-1);
            if(loc!=-1)
                System.out.println("Element found at location "+(loc+1));
            else
                System.out.println("Element not found!");

            System.out.print("Do another search? [y/n]  ");
            ch=in.next().charAt(0);

        }while(ch=='y'||ch=='Y');
    }

    static int binarySearch(int[] array,int key,int start,int end)
    {
        if(start==end)
        {
            if(array[start]==key)
                return start;
            else
                return -1;
        }
        else
        {
            int mid=(start+end)/2;

            if(array[mid]==key)
                return mid;
            else if(array[mid]>key)
                return binarySearch(array,key,start,mid);
            else
                return binarySearch(array,key,mid+1,end);
        }
    }

}