calc pi by rand()

pi-calc-playground.rs

use proconio::input;
use rand::prelude::*;

fn main() {
    input! {
        n: usize
    };
    let mut rng = rand::thread_rng();

    let mut cnt = 0.0;
    for _ in 0..n {
        let x: f64 = rng.gen_range(0.0..1.0);
        let y: f64 = rng.gen_range(0.0..1.0);
        if x * x + y * y <= 1.0 {
            cnt += 1.0;
        }
    }
    println!("{}", 4.0 * cnt / n as f64);
}