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

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Solutions

ogaca42

2 hours ago

2.32ms

86.68kb

pub fn fibonacci(n: u32) -> u32 {    
    let mut values = vec![0, 1];
    for i in 2..n + 1 {
        values.push(values[(i-1) as usize] + values[(i-2) as usize]);
    }
    values[n as usize]
}

Maki-SIO

4 hours ago

2.48ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    if n <= 1 {
        return n;
    }
    let (mut a, mut b) = (0, 1);
    for _ in 2..=n {
        b = a + b;
        a = b - a;
    }
    b
}

Maxence Potier

Mxn-ptr

5 hours ago

2.05ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    if n <= 1 {
        return n;
    }
    let (mut a, mut b) = (0, 1);
    for _ in 2..=n {
        b = a + b;
        a = b - a;
    }
    b
}

ShileiShen

5 hours ago

2.15ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    if 0 == n {
        return 0;
    }
    if 1 == n {
        return 1;
    }
    let mut a = 0;
    let mut b = 1;
    let mut c: u32;
    for _ in 2..=n {
        c = a + b;
        a = b;
        b = c;
    }
    b
}

ShileiShen

5 hours ago

2.12ms

81.28kb

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

jamtg

6 hours ago

2.33ms

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)
    }
}

Daniel Yan

yansq

8 hours ago

2.13ms

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)
    }
}

funny_233

funny233-github

11 hours ago

2.22ms

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)
    }
}

zelsazgh

13 hours ago

2.19ms

81.28kb

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

José Bernardo

jose-bernardo

16 hours ago

2.27ms

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)
}

Delta Regeer

digitalresistor

20 hours ago

2.19ms

81.28kb

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

Carlos Arias

carlos-quantexai

21 hours ago

2.11ms

81.28kb

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

Logan Radloff

radloffl

a day ago

2.88ms

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)
    }
}

retinotopic

a day ago

2.09ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    let mut slide1: u32 = 0;
    let mut slide2: u32 = 1;
    let mut temp: u32 = 0;
    for i in 0..n {
        temp = slide1;
        slide1 = slide2 + slide1;
        slide2 = temp;
    }
    return slide1;
}

retinotopic

a day ago

2.31ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    let mut slide1: u32 = 0;
    let mut slide2: u32 = 1;
    let mut temp: u32 = 0;
    for i in 0..n {
        temp = slide1;
        slide1 = slide2 + slide1;
        slide2 = temp;
    }
    return slide1;
}

今何求

jhq223

2 days ago

2.10ms

81.28kb

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

Will Barnett

xbarnett

2 days ago

2.10ms

81.28kb

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

Mikhail

mk-comm

2 days ago

2.03ms

81.28kb

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

Johnchoi913

2 days ago

2.10ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    let mut count: u32 = 0;
    let (mut a, mut b) = (0, 1);
    while count < n {
        (a,b) = (b, a + b);
        count += 1;
    }
    a
}

majesticalcreature

2 days ago

2.20ms

81.28kb

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

Laurențiu STOLERIU

LaurentiuStoleriu

2 days ago

2.16ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    let mut fibO: u32 = 0;
    let mut fibN: u32 = 1;
    let mut local_n = n;
    if local_n == 0 {
        return fibO;
    }
    if local_n == 1 {
        
        return fibN;
    } else {
        while local_n > 1 {
            fibN = fibN + fibO;
            fibO = fibN - fibO;
            local_n = local_n - 1;
        }
        return fibN;
    }
}

Matei Stefanescu

matei

2 days ago

2.13ms

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) 
    }
}

sander-b-postnl

2 days ago

1.98ms

81.28kb

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

Edoardo A. Morosanu

edoardo-morosanu

2 days ago

2.17ms

81.28kb

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

i5.650

i5-650

2 days ago

2.18ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    if n == 0 {
        return 0;
    }
    let mut n1 = 0;
    let mut n2 = 1;
    let mut cn = n;
    for _ in 1..n {
        cn = n1 + n2;
        n1 = n2;
        n2 = cn;
    }
    cn
}

amassare

2 days ago

2.21ms

81.28kb

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

Oleksandr Romanov

alexromanov

2 days ago

2.18ms

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);
    }
}

Zava

zavakid

2 days ago

2.25ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    fn go(n: u32, n1: u32, n2: u32) -> (u32, u32) {
        if n == 0 {
            (n1, n2)
        } else {
            go(n-1, n2, n1+n2)
        }
    }
    match n {
        0 => 0,
        1 => 1,
        _ => go(n - 1, 0, 1 ).1
    }
    
}

IdoPort

2 days ago

2.23ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    let mut n0 = 0;
    let mut n1 = 1;
    if n == 0 {
        return n0;
    }
    if n == 1 {
        return n1;
    }
    let mut fib = 0;
    for _ in 0..n-1 {
        fib = n0 + n1;
        n0 = n1;
        n1 = fib;
    }
    fib
}

IdoPort

2 days ago

2.26ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    let mut n0 = 0;
    let mut n1 = 1;
    if n == 0 {
        return n0;
    }
    if n == 1 {
        return n1;
    }
    let mut fib = 0;
    for _ in 0..n-1 {
        fib = n0 + n1;
        n0 = n1;
        n1 = fib;
    }
    fib
}

Ustin

2 days ago

2.25ms

81.28kb

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

Dylan Park

dylan-park

3 days ago

2.10ms

81.28kb

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

至尊宝

shankun

3 days ago

2.14ms

81.28kb

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

Parallaxes

3 days ago

2.33ms

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),
    }
}

Xinoi

3 days ago

2.21ms

81.28kb

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

Adi

Aditeya

3 days ago

2.17ms

81.28kb

pub fn fibonacci(mut n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    if n == 0 { return 0; }
    if n > 0 && n < 3 { return 1; }
    let mut a = 0;
    let mut b = 1;
    n-=1;
    while n > 0 {
        let sum = a+b;
        a = b;
        b = sum;
        n -= 1;
    }
    return b;
}

Stefano Cianciulli

CianciuStyles

3 days ago

2.17ms

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)
    }
}

Ayush Rawat

ayushrawat10

3 days ago

2.27ms

81.28kb

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

Patrik Bjärterot

pbjarterot

3 days ago

2.27ms

81.28kb

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

masteryachty

3 days ago

2.11ms

81.28kb

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

damascussteel21

3 days ago

2.17ms

81.28kb

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

Joel Vicente Filho

kyhou

4 days ago

2.39ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    if n == 0u32 {
        return 0u32;
    };
    if n == 1u32 {
        return 1u32;
    };
    let mut prev: u32 = 0u32;
    let mut sum: u32 = 1u32;
    let mut new_sum: u32 = 0;
    for x in 2..=n {
        new_sum = sum + prev;
        prev = sum;
        sum = new_sum;
    };
    new_sum as u32
}

Abhiyan Chhetri

abhiyan-chhetri

4 days ago

2.21ms

81.28kb

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

Ojash Neopane

oneopane

4 days ago

2.16ms

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),
    }
}

Jiawei Tian

AtJiawei

4 days ago

2.21ms

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)
    }
}

Edgar Christian

edgarcnp

4 days ago

2.18ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    (0..n).fold((0, 1), |(a, b), _| (b, a + b)).0
}

Samuel

Sommos

4 days ago

2.28ms

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)
    }
}

Christian Franzl

wischi-chr

4 days ago

2.14ms

81.28kb

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

Tukan van der Borgh

tukantje

4 days ago

2.18ms

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)
    }
}

Gareth Andrew Lloyd

Ignition

4 days ago

2.28ms

81.28kb

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