Fibonacci

The Fibonacci sequence is a series of numbers in which each number is the sum of the two preceding ones, usually starting with 0 and 1. The sequence starts with 0 and 1, and then each number is the sum of the two preceding ones.

You are given a function fibonacci(n: u32) -> u32 that takes a number n and returns the n-th number in the Fibonacci sequence.

Your job is to implement the function meeting the following requirements:

If given n is 0, the function should return 0.
If given n is 1, the function should return 1.
If given n is greater than 1, the function should return the sum of the two preceding numbers.

Example

Here are some examples of how the behavior of the function should look like:

assert_eq!(fibonacci(0), 0); // Returns 0
assert_eq!(fibonacci(1), 1); // Returns 1
assert_eq!(fibonacci(2), 1); // Returns 1 + 0 = 1
assert_eq!(fibonacci(3), 2); // Returns 1 + 1 = 2
assert_eq!(fibonacci(4), 3); // Returns 2 + 1 = 3
assert_eq!(fibonacci(5), 5); // Returns 3 + 2 = 5
assert_eq!(fibonacci(6), 8); // Returns 5 + 3 = 8
assert_eq!(fibonacci(7), 13); // Returns 8 + 5 = 13

Editor not available on Mobile!

In order to solve the challenge, please visit this page on a desktop computer.

Solutions

Takuro Niitsuma

otakumesi

18 hours ago

3.67ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    if n == 0 {
        return 0
    }
    if n == 1 {
        return 1
    }
    fibonacci(n - 1) + fibonacci(n - 2)
}

dawwestk

2 days ago

4.57ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    match n {
        0 => 0,
        1 => 1,
        _ => fibonacci(n - 1) + fibonacci(n - 2),
    }
}

Dhananjay Pandit

djpandit007

4 days ago

3.37ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    match n {
        0 => 0,
        1 => 1,
        _ => fibonacci(n - 1) + fibonacci(n - 2),
    }
}

PangoSea

kapaseker

4 days ago

4.59ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    if n <= 1 {
        n
    } else {
        fibonacci(n - 1) + fibonacci(n - 2)
    }
}

Sakura

sakkura

8 days ago

3.05ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    if n == 0 {
        return 0;
    } else if n == 1 {
        return 1;
    } else {
        return fibonacci(n-1) + fibonacci(n-2);
    }
}

Tengz Mao

MaoX-Yu

8 days ago

3.55ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    if n == 0 || n == 1 {
        n
    } else {
        fibonacci(n-1) + fibonacci(n-2)
    }
}

mm-yyyy

9 days ago

2.86ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    match n {
        0 => 0,
        1 => 1,
        _ => {
            fibonacci(n - 1) + fibonacci(n - 2)
        },
    }
}

Bugra Okumus

bgraokmush

9 days ago

2.97ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    match n {
        0 => 0,
        1 => 1,
        _ =>  fibonacci(n-1) + fibonacci(n-2),
    }   
}

Dominicm99

9 days ago

2.64ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    match n {
        0 => 0,
        1 => 1,
        _ => fibonacci(n - 1) + fibonacci(n - 2),
    }
}

Ahmet Özcan

ahmetoozcan

9 days ago

3.03ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    if n == 0 {
        return 0;
    } else if n == 1 {
        return 1;
    }
    fibonacci(n-1) + fibonacci(n-2)
}

Mikhail Shutov

mshutov

9 days ago

2.90ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequenc
    return match n {
        0 => 0,
        1 => 1,
        _ => fibonacci(n-2) + fibonacci(n-1)
    }
}

vikingNR

10 days ago

3.29ms

81.28kb

use std::ops::{Div, Sub};
pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    (1.618034_f32.powi(n as i32).sub((1.0_f32.sub(1.618034_f32)).powi(n as i32)).div(5_f32.sqrt())) as u32
}

Pathan Khaleedh Khan

KhaleedhKhan

10 days ago

2.85ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
        match n {
        0 => 0 ,
        1=> 1 , 
        2.. => fibonacci(n-1)+fibonacci(n-2),
    }
}

Jadoski™

oelun-in

10 days ago

3.16ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    if n <= 1 {
        n
    }
    else {
        fibonacci(n-2) + fibonacci (n-1 )
    }
    
}

Sandeep chauhan

ryzen-xp

11 days ago

3.21ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    match n {
        0 => 0 ,
        1=> 1 , 
        2.. => fibonacci(n-1)+fibonacci(n-2),
    }
}

PavelPerna

11 days ago

2.95ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    match n{
        0|1 => n,
        _ => fibonacci(n-1)+fibonacci(n-2)
    }
}

rawar089

11 days ago

3.26ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    if n <= 1 {
        return n
    } else {
        fibonacci(n-1) + fibonacci(n-2)
    }
}

Stan

i2z4

12 days ago

3.84ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    match n {
        0 => 0,
        1 => 1,
        2.. => fibonacci (n - 1) + fibonacci (n - 2),
    }
}

matsuyama-k1

12 days ago

2.94ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    if n == 0 {
        return 0;
    } else if n == 1 {
        return 1;
    }
    return fibonacci(n-2) + fibonacci(n-1);
}

Elviskarani

13 days ago

9.31ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
   
 if n <= 1 {
        return n;
    }
    fibonacci(n - 1) + fibonacci(n - 2)
}

Vlad

mvldmihai

13 days ago

2.77ms

86.68kb

pub fn fibonacci(n: u32) -> u32 {
    let mut v: Vec<u32> = vec![0, 1];
    if n == 0 {
        return v[0];
    }
    else if n == 1 {
        return v[1];
    }
    while v.len() != (n + 1).try_into().unwrap() {
        v.push(v[v.len() - 1] + v[v.len() - 2]);
    }
    v[v.len() - 1]
}

Mohamed Elkebir

elkebirmed

14 days ago

4.28ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    if n <= 1 {
        return n;
    }
    fibonacci(n - 1) + fibonacci(n - 2)
}

Mohamed Elkebir

elkebirmed

14 days ago

3.00ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    if n <= 1 {
        return n;
    }
    fibonacci(n - 1) + fibonacci(n - 2)
}

Rickard Jensen

rjensen

14 days ago

3.12ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    if n <= 1 {
        return n;
    } else {
        return fibonacci(n-2) + fibonacci(n-1);
    }
}

kada-s

sy34

15 days ago

3.39ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    if n <= 1 {
        return n;
    } else {
        return fibonacci(n-2) + fibonacci(n-1);
    }
}

zahrajavar

15 days ago

6.44ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    if n==0{
        return 0;
    }else if n==1{
        return 1;
    }else{
        fibonacci(n-1)+fibonacci(n-2)
    }
    
}

Robin Le Caignec

Le-Caignec

15 days ago

3.18ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    match n {
        0 | 1 => n,
        _ => fibonacci(n-2)+fibonacci(n-1),
    }
}

Zenya Nagata

zenyanagata

16 days ago

3.01ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    if n == 0 {
        return 0;
    }
    if n == 1 {
        return 1;
    }
    let mut prev: u32 = 0;
    let mut cur: u32 = 1;
    for _ in 0..n - 1 {
        let tmp: u32 = prev + cur;
        prev = cur;
        cur = tmp;
    }
    return cur;
}

Yofifi

16 days ago

3.05ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    if n == 0 || n == 1 {
        return n;
    } else {
        return fibonacci(&n-1) + fibonacci(&n-2)
    }
}

goerfra

16 days ago

2.75ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    match n {
        0 | 1 => n,
        _ => fibonacci(n - 1) + fibonacci(n - 2), 
    }
}

karapy

16 days ago

2.72ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    if n == 0 {
        return 0;
    } else if n == 1 || n == 2 {
        return 1;
    } else {
        fibonacci(n - 1) + fibonacci(n - 2)
    }
    
}

Tarokc

17 days ago

3.07ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    if n == 0 || n == 1 {
        n
    }
    else {
        let mut a = 0;
        let mut b = 1;
        let mut c = 0;
        for _ in 1..n {
            c = a + b;
            a = b;
            b = c;
        }
        c
    }
}

Larry Oates

Leafmun-certii

17 days ago

3.02ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    match n {
        n if n < 1 => return 0,
        1 => return 1,
        n if  n > 1 => return fibonacci(n-1) + fibonacci(n-2),
        _ => unreachable!("negitive numbers not implemented"),
    }
}

Larry Oates

Leafmun-certii

17 days ago

3.07ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    match n {
        n if n < 1 => return 0,
        1 => return 1,
        n if  n > 1 => return fibonacci(n-1) + fibonacci(n-2),
        0_u32 | 2_u32..=u32::MAX => todo!(),
    }
}

aey4

17 days ago

3.59ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    return match n{
        0 => 0,
        1 => 1,
        _ => fibonacci(n-1) + fibonacci(n-2)
    };
}

akshayabhattarai

17 days ago

3.05ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    let mut ret = match n{
        0 => 0,
        1 => 1,
        _ => fibonacci(n-1) + fibonacci(n-2)
    };
    return ret;
}

Katsuki Chousa

refiute

18 days ago

3.22ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    match n {
        0 => 0,
        1 => 1,
        _ => fibonacci(n - 1) + fibonacci(n - 2),
    }
}

nedrw

18 days ago

3.07ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    match n {
        0 => 0,
        1 => 1,
        _ => fibonacci(n-1) + fibonacci(n-2),
    }
}

Felix Kiprotich

penscola

18 days ago

2.95ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    match n {
        0 => 0,
        1 => 1,
        _ => fibonacci(n-1) + fibonacci(n-2)
    }
}

Caio César

caiocdcs

18 days ago

3.12ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    if n <= 1 {
        return n;
    }
    fibonacci(n - 1) + fibonacci(n - 2)
}

Yamami

Yamami1221

18 days ago

5.34ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    fn fibo_aux(i: u32, prev: u32, now: u32) -> u32 {if i == 0 {0} else if i == 1 {now} else {fibo_aux(i-1,now,prev+now)}}
    fibo_aux(n,0,1)
}

Mani Yadla

YadlaMani

19 days ago

2.71ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
   
    match n{
        0=> 0,
        1=>1,
        _=>fibonacci(n-1)+fibonacci(n-2)
    }
}

viky

vikyw89

19 days ago

7.05ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    // base case
    if n == 0 {
        return 0 as u32;
    }
    if n == 1 {
        return 1 as u32;
    }
    // recursive case
    return fibonacci(n - 1) + fibonacci(n - 2);
}

doroshtapgh

20 days ago

4.81ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    match n {
        0 => 0,
        1 => 1,
        _ => fibonacci(n - 1) + fibonacci(n - 2)
    }
}

roux g. buciu

adudenamedruby

20 days ago

3.30ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    match n {
        0 => 0,
        1 => 1,
        _ => fibonacci(n-1) + fibonacci(n - 2)
    }
}

Chris

chriswmann

20 days ago

2.80ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    match n {
        0 => 0,
        1 => 1,
        n => {
            fibonacci(n - 1) + fibonacci(n - 2)
        },
    }
}

JeppeFoldberg

20 days ago

2.77ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    match n {
        0 => 0,
        1 => 1,
        _ => fibonacci(n - 1) + fibonacci(n - 2)
    }
}

JeppeFoldberg

20 days ago

2.91ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    if n == 0 {
        0
    } else if n == 1 {
        1
    } else {
        fibonacci(n - 1) + fibonacci(n - 2)
    }
}

chuyuanlinzi

20 days ago

2.65ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    match n {
        0 => 0,
        1 => 1,
        _ => fibonacci(n-1) + fibonacci(n- 2)
    }
}

DistributedDoge

21 days ago

6.88ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    match n{
        0 => 0,
        1 => 1,
        _ => fibonacci(n-1) + fibonacci(n-2)
    }
}