Question

How do i make a recursive binary search that compares two String arrays in java?

Answer 1

// recursive Binary Search

class RecursiveBinarySearch {

    int binarySearch(int arr[], int l, int r, int x)

    {

        if (r >= l) {

            int mid = l + (r - l) / 2;

            // If the element is present at the middle itself

            if (arr[mid] == x)

                return mid;

            // If element is smaller than mid, then it can only

            // be present in left subarray

else if (arr[mid] > x)

                return binarySearch(arr, l, mid - 1, x);

            // Else the element can only be present in right

            // subarray

else

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

        }

else

        // We reach here when element is not present in array

return -1;

    }

    // Driver method to test above

    public static void main(String args[])

    {

RecursiveBinarySearch ob = new RecursiveBinarySearch();

        int arr[] = { 2, 3, 4, 10, 40 };

        int n = arr.length;

        int x = 10;

        int result = ob.binarySearch(arr, 0, n - 1, x);

        if (result == -1)

            System.out.println("Element not present");

        else

            System.out.println("Element found at index " + result);

    }

}