Fibonacci Number
Updated Jan 31, 2026
Problem
Given an integer n, output the nth Fibonacci number.
The Fibonacci sequence is: 0, 1, 1, 2, 3, 5, 8, 13, 21, ...
where F(0) = 0, F(1) = 1, and F(n) = F(n-1) + F(n-2) for n > 1.
Constraints
0 <= n <= 30
Examples
Example 1
Input:
n = 0
Output:
0
Example 2
Input:
n = 1
Output:
1
Example 3
Input:
n = 10
Output:
55
Function Signature
def fib(self, n: int) -> int
How to Submit
Implement a Solution class with a fib method.
Your method will be called with the input parameters and should return the answer.