class BinarySearchApp
{
    int binarySearch(int arr[], int l, int r, int x)
    {
        if (r>=l)
        {
            int mid = l + (r - l)/2;

            if (arr[mid] == x)
               return mid;

            if (arr[mid] > x)
               return binarySearch(arr, l, mid-1, x);

            return binarySearch(arr, mid+1, r, x);
        }
        return -1;
    }

    public static void main(String args[])
    {
        BinarySearchApp obj = new BinarySearchApp();
        int arr[] = {3,5,9,10,20};
        int n = arr.length;
        int searchKey = 9;
        System.out.println("Array Elements:");
        for(int i : arr) System.out.print(i + " ");
        System.out.println();
        System.out.println("Searching for " + searchKey);
        int result = obj.binarySearch(arr,0,n-1,searchKey);
        if (result == -1)
            System.out.println("Element not found");
        else
            System.out.println("Element found at index " + result);
    }
}