JAVA:

Implement an efficient recursive fibonacci(int n) method that returns a Pair object containing the nth and (n+1)the Fibonacci numbers.

That means fibonacci(0) will return (0,1), fibonacci(1) will return (1,1), fibonacci(2) will return (1,2) and so on.

(Note: the pairs (0,1), (1,1) etc. are actually Pairs of Long objects , not ints .)

Your method will be called with some big values of n, so it must be efficient to avoid a timeout.

Hint: This can be implemented using four lines of code.