Approximate pi

approxpi.rs

use rand::prelude::*;

fn main() {
    println!("pi = {}", approx(1000000));
}

fn approx(count: u64) -> f64 {
    let mut rng = rand::thread_rng();
    let mut circle = 0;
    for _ in 0..count {
        let (a,b):(f64,f64) = (rng.gen(),rng.gen());
        let (x,y) = (a * 2.0 - 1.0, b * 2.0 - 1.0);
        if x.powf(2.0) + y.powf(2.0) < 1.0 {
            circle += 1;
        }
    }
    let ratio = circle as f64 / count as f64;
    ratio * 4.0
}