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

Kenneth Love

kennethlove

8 minutes ago

3.04ms

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)
}

Tobiasz

tobiaszfilar

an hour ago

5.44ms

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 {
        return fibonacci(n - 1) + fibonacci(n - 2);
    }
}

kylenoteboom

6 hours ago

3.17ms

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)
}

Nanle100

7 hours ago

2.83ms

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 if n > 1 {
         return fibonacci(n - 1) + fibonacci(n - 2);
    } else {
        0
    }
}

takes-ki

8 hours ago

2.84ms

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)
    }
    
}

Jaden Wijata

xenonminer

10 hours ago

2.96ms

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)
    }
}

Jim Lawton

jimlawton

21 hours ago

2.78ms

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)
    }
}

Esteban Soba

XtebanUy

a day ago

4.50ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    let mut n_minus2 = 0;
    let mut n_minus1 = 1;
    match n {
        0 => n_minus2,
        1 => n_minus1,
        _ => {
            for _ in 2..=n 
            {
                let swap = n_minus1;
                n_minus1 = n_minus1 + n_minus2;
                n_minus2 = swap;
            }
            n_minus1
        }
    }
}

5822791760

a day ago

2.80ms

81.28kb

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

Markus Bergkvist

mbergkvist

a day ago

2.73ms

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)
    }
}

facat

a day ago

3.87ms

81.28kb

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

Ando “Thor” Nando

DivineGod

2 days ago

3.20ms

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),
    }
}

Andreas

StimhackSoftware

2 days ago

3.57ms

85.89kb

pub fn fibonacci(n: u32) -> u32 {
    if n > 1 {
        let mut n1 = 1;
        let mut n2 = 1;
        for _i in 2..n {
            let new = n1 + n2;
            n1 = n2;
            n2 = new;
        }
        n2
    } else if n == 1{
        1
    } else {
        0
    }
}

mehdihmr

2 days ago

2.80ms

81.28kb

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

mehdihmr

2 days ago

3.03ms

81.28kb

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

Mister Woody

MisterWoody

2 days ago

2.90ms

81.28kb

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

Algorab

2 days ago

3.82ms

81.28kb


 pub fn fibonacci(n: u32) -> u32 {
    if n == 0 {
        return 0; // Handle edge case for 0 terms
    } else if n == 1 {
        return 1; // Handle edge case for 1 term
    }
    let mut a = 0;
    let mut b = 1;
    for _ in 2..=n {
        let temp = a + b;
        a = b;
        b = temp;
    }
    b
}

Stefan Roas

sroas

2 days ago

2.78ms

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)
}

Felipe Balbi

felipebalbi

3 days ago

3.41ms

81.28kb

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

xiuchiliudu

3 days ago

2.77ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
     let mut num1 = 0;
    let mut num2 = 1;
    if n == 0 {
        return 0;
    } else if n == 1 {
        return 1;
    }
    for i in 2..=n {
        if i % 2 == 0 {
            num1 = num1 + num2;
        } else {
            num2 = num1 + num2;
        }
    }
    if n % 2 == 0 {
        num1
    } else {
        num2
    }
}

Daniel Petrov

danielmpetrov

3 days ago

3.10ms

81.28kb

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

qiyuan711

3 days ago

3.09ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    let mut a = 0;
    let mut b = 1;
    let mut count = n;
    if count == 0 {
        a
    } else if count == 1 {
        b
    } else {
        while count > 1 {
            let c = a + b;
            a = b;
            b = c;
            count -= 1 
        }
        b
    }
}

Jan Willems

3 days ago

3.35ms

81.28kb

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

yoakemae

4 days ago

2.93ms

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);
}

tinthid

4 days ago

2.82ms

81.28kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    let mut fib: Vec<u32> = vec![];
    fib.extend(vec![0,1]);
    let mut i: usize = 2;
    while i <= n as usize{
        fib.push(fib[i-2] + fib[i-1]);
        i += 1;
    }
    fib[n as usize]
}

Nicky Thorne

nickythorne

4 days ago

3.02ms

81.28kb

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

Philip Mercer

DV-13

4 days ago

3.17ms

81.28kb

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

Jörg Erdmenger

joeslow

4 days ago

3.23ms

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)
    }
}

RonaldoArayadev

4 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-1) + fibonacci(n-2);
}

martin-unit

4 days ago

2.94ms

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)
}

Elizabeth Doughty

Thymelizabeth

5 days ago

3.45ms

81.28kb

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

s.konishi

konishu

6 days ago

3.87ms

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)
    }
    
}

Masayuki Sunahara

tamanishi

6 days ago

2.92ms

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)
}

devarajang

6 days ago

2.77ms

81.28kb

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

oDqnger

6 days ago

3.09ms

86.68kb

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

nichideropa

6 days ago

30.10ms

81.28kb

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

nichideropa

6 days ago

3.44ms

81.28kb

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

Jan

jeypiti

6 days ago

2.92ms

81.28kb

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

Sidhanta-Bkup

7 days ago

2.90ms

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)    
}

0xsmarter

7 days ago

2.75ms

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),
        
    }
}

t3stlab

7 days ago

3.83ms

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),
    }
}

aidan1magee

7 days ago

2.81ms

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),
    }
}

tsuchiya-d

tsucchinoko

7 days ago

2.64ms

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),
    }
}

Thitiworada

Kobeieii

7 days ago

3.16ms

86.68kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    let mut stack = vec![0, 1];
    
    for i in 0..n+1 {
        if i > 1 {
            let fib_n = stack[(i-2) as usize] + stack[(i-1) as usize];
            stack.push(fib_n);
        }
    }
    stack[n as usize]
}

Thitiworada

Kobeieii

7 days ago

4.20ms

86.68kb

pub fn fibonacci(n: u32) -> u32 {
    // TODO: Implement the Fibonacci sequence
    let mut stack = vec![0, 1];
    
    for i in 0..n+1 {
        if i > 1 {
            let fib_n = stack[(i-2) as usize] + stack[(i-1) as usize];
            stack.push(fib_n);
        }
    }
    stack[n as usize]
}

Ankeet Parikh

ankeetparikh

8 days ago

2.98ms

81.28kb

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

maxvi

8 days ago

2.95ms

81.28kb

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

Gert Vervoort

gjmvervoort

8 days ago

3.81ms

81.28kb

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

Lauri Sarap

LauriSarap

8 days ago

3.08ms

81.28kb

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

Nt2311

nt2311-vn

8 days ago

3.01ms

81.28kb

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