299. Fibonacci Number

The Fibonacci numbers, commonly denoted F(n) form a sequence, called the Fibonacci sequence, such that each number is the sum of the two preceding ones, starting from 0 and 1. That is,

  • F(0) = 0, F(1) = 1
  • F(n) = F(n - 1) + F(n - 2), for n > 1.

Given n, calculate F(n).

Example 1:

Input : n = 2

Output : 1

Explanation : F(2) = F(1) + F(0) => 1 + 0 => 1.

Example 2:

Input : n = 3

Output : 2

Explanation : F(3) = F(2) + F(1) => 1 + 1 => 2.

Now Your Turn!

Pick the correct output for the given input

Input : n = 6

Still unsure what the problem is asking ?

Let’s go through a few more examples, step by step, to make it clearer.

Constraints:

  • 0 <= n <= 20
0
class Solution {
public:
int fib(int n) {
//your code goes here
}
};
Test Case

Input:

N
to save your code