advent_of_code_2021/december_4/src/main.rs

use std::borrow::Borrow;
use std::fs::File;
use std::io::{BufReader};
use std::io::prelude::*;
use std::vec;

struct Board {
    contents: Vec<Vec<u32>>,
    matched: Vec<Vec<bool>>,
    size: usize,
    won: bool
}


fn main(){
    let file = File::open("./input.txt").expect("Read failed");
    let reader = BufReader::new(file);

    let mut line_vec = Vec::new();


    for line in reader.lines(){
        let line_as_string = line.unwrap();
        line_vec.push(line_as_string);
    }

    let first_line = &line_vec[0];
    let input_sequence_str = first_line.split(',').collect::<Vec<&str>>();
    let input_sequence_u32: Vec<u32> = input_sequence_str.iter().map(|x| x.parse::<u32>().unwrap()).collect();

    let mut boards: Vec<Board> = Vec::new();

    let mut temp_board: Vec<Vec<u32>> = Vec::new();

    let mut final_score = 0;

    let mut last_winning_index = 0;
    let mut last_winning_score = 0;

    for line_nr in 2..line_vec.len() {
        let current_line = line_vec[line_nr].to_owned();
        if current_line == "" {
            let mut matched_vec = Vec::new();
            for _ in 0..temp_board.len(){
                matched_vec.push(vec![false; temp_board.len()])
            }
            boards.push(Board {contents:temp_board.to_owned(), matched:matched_vec, size : temp_board.len(), won: false});
            temp_board = Vec::new();
        } else {
            let temp_vec_str = current_line.split_whitespace().collect::<Vec<&str>>();
            let line_as_u32_vec: Vec<u32> = temp_vec_str.iter().map(|x| x.parse::<u32>().unwrap()).collect();
            temp_board.push(line_as_u32_vec);
        }
    }

    // If there is no trailing newline the last board gets stuck in the temp_board vec
    if temp_board.len() != 0 {
        let mut matched_vec = Vec::new();
        for _ in 0..temp_board.len(){
            matched_vec.push(vec![false; temp_board.len()])
        }
        boards.push(Board {contents:temp_board.to_owned(), matched:matched_vec, size : temp_board.len(), won: false});

    }

    for input in input_sequence_u32{
        println!("processing {}", input);
        for i in 0..boards.len(){
            boards[i] = check_for_hit(boards[i].borrow(), input);
            print!("");
        }
        for i in 0..boards.len(){
            if check_if_won(boards[i].borrow()){
                boards[i].won = true;
                if final_score == 0 {
                    final_score = calculate_score(boards[i].borrow(), input);
                }
            }

        }
        let mut temp_remaining = 0;
        let mut remaining_index = 0;
        for i in 0..boards.len(){
            if !boards[i].won {
                temp_remaining += 1;
                remaining_index = i;
            }
        }

        if temp_remaining == 0 && last_winning_score == 0{
            last_winning_score = calculate_score(boards[last_winning_index].borrow(), input);
        }
        last_winning_index = remaining_index;


    }

    println!("Result score: {}", final_score);
    println!("Last winning score: {}", last_winning_score);
}


fn check_for_hit(in_board: &Board, in_number: u32) -> Board {
    let mut out_board = Board{contents:in_board.contents.to_owned(), matched:in_board.matched.to_owned(), size:in_board.size.to_owned(), won: false};
    for (index_l, line) in out_board.contents.iter().enumerate() {
        for (index_e, element) in line.iter().enumerate(){
            if *element == in_number{
                out_board.matched[index_l][index_e] = true;
            }

        }
    }
    return  out_board;
}

fn check_if_won(in_board: &Board) -> bool {
    let size = in_board.size;
    let matched_vec = in_board.matched.to_owned();


    //Check Vertical
    for column in 0..size {
        for row in 0..size{
            if matched_vec[row][column] == false {
                break;
            } else if row == size -1 {
                return true;
            }
        }
    }

    //Check horizontal
    for line in matched_vec{
        for (pos, element) in line.iter().enumerate() {
            if !element {
                break;
            } else if pos == size - 1 {
                return true;
            }
        }
    }



    return false;
}

fn calculate_score(in_board: &Board, current_number: u32) -> u32 {
    let matched_vec = in_board.matched.to_owned();
    let content_vec = in_board.contents.to_owned();
    let size = in_board.size;
    let mut score = 0;

    for line in 0..size{
        for element in 0..size{
            if !matched_vec[line][element] {
                score += content_vec[line][element];
            }
        }
    }
    return score * current_number;
}