teryror

use num_bigint::BigUint;
use num_traits::ToPrimitive;

// calculate the binomial coefficient `n choose k`
fn binomial_coefficient(n: u32, k: u32) -> u64 {
    let mut result = BigUint::from(1u32);
    for i in 0..k {
        result = (result * (n - i)) / (i + 1);
    }
    result.to_u64().unwrap()

teryror

fn binomial_coefficient(n: u32, k: u32) -> u128 {
    let mut res = 1u128;
    for i in 0..k {
        res = (res * (n - i) as u128) / (i + 1) as u128;
    }
    res
}

fn neg_binom_pmf(k: u32, r: u32, p: f64) -> f64 {
    assert!(r > 0);

teryror

fn binomial_coefficient(n: u32, k: u32) -> u128 {
    let mut res = 1u128;
    for i in 0..k {
        res = (res * (n - i) as u128) / (i + 1) as u128;
    }
    res
}

fn neg_binom_pmf(k: u32, r: u32, p: f64) -> f64 {
    assert!(r > 0);

teryror

// Calculate the area of a generalized ellipse (abs(x/a)^n + abs(y/b)^n = 1).
// I'm considering this as the metric to minimize for a weird optimization
// problem, where this would be evaluated _a lot_, so I tried making this
// as fast & simple as possible.

pub fn area_of_superellipse(exponent: f64, semi_axes: (f64, f64)) -> f64 {
    let n = exponent;
    let (a, b) = semi_axes;

    // This method was derived from the following formula:

teryror

/// Const evaluatable Rust implementation of Vose's Alias Method, as described
/// by Keith Schwarz at https://www.keithschwarz.com/darts-dice-coins/
/// 
/// In brief, this is an O(n) precomputation, which allows sampling an arbitrary
/// finite probability distribution in O(1) time, by first simulating a fair
/// n-sided die, followed by a biased coin.
///
/// Because floating point arithmetic cannot be used in const functions, this is
/// built to operate on integer weights, rather than precomputed probabilities.
/// 

teryror

use scraper::{Html, Selector};

use std::collections::HashMap;

fn main() {
    let source_sites: &[&[&str]] = &[
        &[
            "https://tvtropes.org/pmwiki/pmwiki.php/BreakingBad/TropesAToB",
            "https://tvtropes.org/pmwiki/pmwiki.php/BreakingBad/TropesCToD",
            "https://tvtropes.org/pmwiki/pmwiki.php/BreakingBad/TropesEToL",