50 lines
1.9 KiB
Rust
50 lines
1.9 KiB
Rust
|
use std::io::{self, BufRead};
|
||
|
|
|
||
|
|
fn split_into_numbers(x: &str) -> impl Iterator<Item = i32> + '_ {
|
||
|
|
return x.split(' ').filter(|&n| {n != "" && n != " "}).map(|n| n.parse::<i32>().unwrap());
|
||
|
|
}
|
||
|
|
|
||
|
|
fn main() {
|
||
|
|
let input = "input.txt";
|
||
|
|
let lines = read_lines(&input);
|
||
|
|
let n_cards: usize = read_lines(&input).count();
|
||
|
|
let mut cards: Vec<u32> = vec![1; n_cards];
|
||
|
|
let mut sum_points: u32 = 0;
|
||
|
|
// number of copies per card
|
||
|
|
for (i, line) in lines.enumerate() {
|
||
|
|
let mut points: u32 = 0;
|
||
|
|
let mut n_matches: usize = 0;
|
||
|
|
let Ok(card) = line else { panic!("Line not ok"); };
|
||
|
|
let Some(colon) = card.find(':') else { panic!("Could not find ':'"); };
|
||
|
|
let Some(pipe) = card.find('|') else { panic!("Could not find '|'"); };
|
||
|
|
// let split_into_numbers = |x: &str| { return x.split(' ').filter(|&n| {n != "" && n != " "}).map(|n| n.parse::<i32>().unwrap()); };
|
||
|
|
let winning_numbers: Vec<i32> = split_into_numbers(&card[colon+2..pipe-1]).collect();
|
||
|
|
for number in split_into_numbers(&card[pipe+2..]) {
|
||
|
|
if winning_numbers.contains(&number) {
|
||
|
|
// task 1
|
||
|
|
if points == 0 { points = 1; }
|
||
|
|
else { points <<= 1; }
|
||
|
|
// task 2
|
||
|
|
if points == 0 { points = 1; }
|
||
|
|
n_matches += 1;
|
||
|
|
}
|
||
|
|
}
|
||
|
|
// task 1
|
||
|
|
sum_points += points;
|
||
|
|
// task 2: add #copies(card i) to the next n_matches cards
|
||
|
|
for j in i+1..i+1+n_matches {
|
||
|
|
cards[j] += cards[i];
|
||
|
|
}
|
||
|
|
}
|
||
|
|
println!("Total points: {}", sum_points);
|
||
|
|
println!("Total number of cards: {}", cards.iter().sum::<u32>());
|
||
|
|
}
|
||
|
|
|
||
|
|
fn read_lines<P>(filename: P) -> io::Lines<io::BufReader<std::fs::File>>
|
||
|
|
where P: AsRef<std::path::Path>, {
|
||
|
|
return match std::fs::File::open(filename) {
|
||
|
|
Err(why) => panic!("Could not open file. {}", why),
|
||
|
|
Ok(file) => std::io::BufReader::new(file).lines()
|
||
|
|
};
|
||
|
|
}
|