// Java implementation of recursive Binary Search
class BinarySearch {
// Returns index of target if it is present in arr else return -1
int binarySearch(int arr[], int first, int last, int target)
{
if (last >= first) {
int mid = first + (last - first) / 2;
// if element is present in the middle
if (arr[mid] == target)
return mid;
// If element is smaller than mid, then it can only be present in first subarray
if (target < arr[mid])
return binarySearch(arr, first, mid - 1, target);
// Else the element can only be present in the second subarray
return binarySearch(arr, mid + 1, last, target);
}
// We reach here when element is not present
// in array
return -1;
}
// Driver method to test above
public static void main(String args[])
{
BinarySearch ob = new BinarySearch();
int arr[] = { 2, 3, 4, 10, 40 };
int length = arr.length;
int target = 10;
int result = ob.binarySearch(arr, 0, length - 1, target);
if (result == -1)
System.out.println("Element not present");
else
System.out.println("Element found at index " + result);
}
}