Fibonacci sum for the given number
Problem description :
In mathematics, the Fibonacci numbers are the numbers in the following integer sequence:
0, 1, 1, 2, 3, 5, 8, 13, 21, 34, 55, 89, 144, ...
In mathematical terms, the sequence F(n) of Fibonacci numbers is defined by the recurrence relation
F(n) = F(n-1) + F(n-2), with seed values F(0) = 0, F(1) = 1, F(2) = 1.
Input : A number >= 0
Output : A Number
Logic :
- Cached the already calculated fibonacci numbers (aka dynamic programming).
- If the number is not calculated then call the function again (aka recurssion).