oxymcts 0.1.0

use noisy_float::prelude::{n64, Float};

use crate::aliases::{Nat, Num};

/// Calculates the uct_value.
#[inline]
pub fn uct_value(parent_visits: Nat, sum_rewards: f64, node_visit: Nat, c: f64) -> Num {
    let sum_rewards = n64(sum_rewards);
    let exploitation_param = sum_rewards / node_visit as f64;
    let exploration_param = (n64(parent_visits as f64).ln() / (node_visit as f64)).sqrt();
    exploitation_param + n64(c) * exploration_param
}

#[test]
fn test_uct_value() {
    assert!((uct_value(500, 0., 10, 2.0_f64.sqrt()) - 1.339088).abs() < 0.00001)
}