aoc_day2.rs

use std::fs;
use std::collections::HashMap;

struct RPS {
    name: String,
    points: u32,
    outcomes: HashMap<String, String>,
    reverse_outcomes: HashMap<String, String>
}

fn init_rps(val: &String) -> RPS {
    match val.as_str() {
        "X" | "A" | "rock" => {
            RPS { 
                name: "rock".to_string(),
                points: 1,
                outcomes: HashMap::from([
                    ("rock".to_string(), "D".to_string()), 
                    ("paper".to_string(), "L".to_string()), 
                    ("scissors".to_string(), "W".to_string())
                    ]
                ),
                reverse_outcomes: HashMap::from([
                    ("Y".to_string(), "rock".to_string()), 
                    ("Z".to_string(), "paper".to_string()), 
                    ("X".to_string(), "scissors".to_string())
                    ]
                )
            }
        },
        "Y" | "B" | "paper" => {
            RPS { 
                name: "paper".to_string(),
                points: 2,
                outcomes: HashMap::from([
                    ("rock".to_string(), "W".to_string()), 
                    ("paper".to_string(), "D".to_string()), 
                    ("scissors".to_string(), "L".to_string())
                    ]
                ),
                reverse_outcomes: HashMap::from([
                    ("X".to_string(), "rock".to_string()), 
                    ("Y".to_string(), "paper".to_string()), 
                    ("Z".to_string(), "scissors".to_string())
                    ]
                )
            }
        },
        "Z" | "C" | "scissors" => {
            RPS { 
                name: "scissors".to_string(),
                points: 3,
                outcomes: HashMap::from([
                    ("rock".to_string(), "L".to_string()), 
                    ("paper".to_string(), "W".to_string()), 
                    ("scissors".to_string(), "D".to_string())
                    ]
                ),
                reverse_outcomes: HashMap::from([
                    ("Z".to_string(), "rock".to_string()), 
                    ("X".to_string(), "paper".to_string()), 
                    ("Y".to_string(), "scissors".to_string())
                    ]
                )
            }
        },
        &_ => {
            RPS {
                name: "none".to_string(),
                points: 0,
                outcomes: HashMap::from([("A".to_string(), "L".to_string())]),
                reverse_outcomes: HashMap::from([("A".to_string(), "L".to_string())])
            }
        }
    }
}

fn main() {
    let strat = fs::read_to_string("input.txt").unwrap();
    let mut total = 0;
    let mut total_strat = 0;
    let round_values = HashMap::from([("W".to_string(), 6), ("D".to_string(), 3), ("L".to_string(), 0)]);
    let new_strat = HashMap::from([("X".to_string(), "L".to_string()), ("Y".to_string(), "D".to_string()), ("Z".to_string(), "W".to_string())]); 
    for line in strat.lines() {
        let round_input: Vec<&str> = line.split(" ").collect();
        let opponent_input = round_input[0].to_string();
        let my_strat = round_input[1].to_string();
        let opponent_rps = init_rps(&opponent_input);
        let my_rps = init_rps(&my_strat);
        total += my_rps.points + round_values[&my_rps.outcomes[&opponent_rps.name]];
        total_strat += round_values[&new_strat[&my_strat]] + init_rps(&opponent_rps.reverse_outcomes[&my_strat]).points;
    }
    println!("{}", total);
    println!("{}", total_strat);
}