#![allow(dead_code)]
#![allow(unused_variables)]
#![allow(unused_mut)]
use std::collections::HashMap;
use std::env;
use std::fs::File;
use std::io::Read;

fn dfs(design: &str, tokens: &Vec<&str>) -> i64 {
    if design.len() == 0 {
        return 1;
    }

    for t in tokens {
        if design.starts_with(t) {
            let ret = dfs(&design[t.len()..], tokens);
            if ret == 1 {
                return 1;
            }
        }
    }
    return 0;
}

fn dfs2<'a>(design: &'a str, tokens: &Vec<&str>, lut: &mut HashMap<&'a str, i64>) -> i64 {
    if design.len() == 0 {
        return 1;
    }

    if let Some(n) = lut.get(design) {
        return *n;
    }

    let mut ret = 0;
    for t in tokens {
        if design.starts_with(t) {
            let s = &design[t.len()..];
            let n = dfs2(s, tokens, lut);
            lut.insert(s, n);
            ret += n;
        }
    }
    return ret;
}

fn main() {
    let args: Vec<String> = env::args().collect();
    let filename = if args.len() == 1 {
        "in/".to_owned() + args[0].split('/').last().unwrap() + ".pzl"
    } else {
        args[1].clone()
    };
    let mut f = File::open(filename).expect("cannot open file");
    let mut content = String::new();
    f.read_to_string(&mut content).expect("cannot read file");
    let (para1, para2) = content.trim_end().split_once("\n\n").unwrap();

    let mut tokens: Vec<&str> = Vec::new();
    for s in para1.split(", ") {
        tokens.push(s);
    }

    let mut designs: Vec<&str> = Vec::new();
    for s in para2.split("\n") {
        designs.push(s);
    }
    //println!("{:?}", tokens);
    //println!("{:?}", designs);

    let mut res1 = 0;
    let mut res2 = 0;
    for d in designs {
        res1 += dfs(d, &tokens);

        let mut lut: HashMap<&str, i64> = HashMap::new();
        res2 += dfs2(d, &tokens, &mut lut);
    }

    println!("res1: {}", res1);
    println!("res2: {}", res2);
    assert_eq!(res1, 240);
    assert_eq!(res2, 848076019766013);
}