Demo rust code for calculating Greatest Common Denominators using Euclidian Algorithm

gcd.rs

use std::time::Instant;

const ITERATIONS: i32 = 100000000;

fn main() {
    let mut line = String::new();
    println!("Input your numbers: ");
    let _ = std::io::stdin().read_line(&mut line).unwrap();
    let mut split = line.split_whitespace();
    let a = split.next().unwrap().parse().unwrap();
    let b = split.next().unwrap().parse().unwrap();

    let mut result: i32 = 0;
    let mut rounds: i32 = 0;

    let start_time = Instant::now();

    for _ in 0..ITERATIONS { 
        (result, rounds) = gcd_mut(a,b);
    }

    let finish_time = Instant::now();

    println!("Mutable T GCD: {} Rounds: {}, Duration: {:?} for {} iterations",result,rounds,finish_time.duration_since(start_time),ITERATIONS);

    let start_time = Instant::now();

    for _ in 0..ITERATIONS { 
        (result, rounds) = gcd_immut(a,b);
    }

    let finish_time = Instant::now();

    println!("Immutable T GCD: {} Rounds: {}, Duration: {:?} for {} iterations",result,rounds,finish_time.duration_since(start_time),ITERATIONS);

}

fn gcd_mut(mut a: i32, mut b: i32) -> (i32, i32) {
    let mut rounds = 0;
    
    let mut t: i32 = 0;

    while b != 0 {
        t = b;
        b = a % b;
        a = t;

        rounds += 1;
    }

    (a,rounds)
}

fn gcd_immut(mut a: i32, mut b: i32) -> (i32, i32) {
    let mut rounds = 0;
    
    while b != 0 {
        let t = b;
        b = a % b;
        a = t;

        rounds += 1;
    }

    (a,rounds)
}