make fast

Bibonacci is the stepbrother of Fibonacci and unfortunately, he is not quite famous as Fibonacci. His numbers are defined as follows: b(0) = 1 b(1) = 2 b(2) = 3 b(n) = b(n-1) *b(n-2) + b(n-3) Write a function to calculate binonacci numbers, Hint: your function should be like int bibonacci(int x)