Method fib

509-fibonacci-number.rs:8–16

(n: i32)

impl Solution {
    pub fn fib(n: i32) -> i32 {
        if n == 0 {
            0
        } else if n == 1 {
            1
        } else {
            Self::fib(n-1) + Self::fib(n-2)
        }
    }

    pub fn fib_dp(n: i32) -> i32 {
        let mut dp = vec![0; 31];