106 lines
2.4 KiB
Rust
106 lines
2.4 KiB
Rust
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use std::{env, fs};
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fn read_input(path: &str) -> String {
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fs::read_to_string(path).expect("Cannot read file.")
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}
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fn add(a: u64, b: u64) -> u64 {
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a + b
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}
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fn mul(a: u64, b: u64) -> u64 {
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a * b
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}
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fn concat(a: u64, b: u64) -> u64 {
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format!("{a}{b}").parse().unwrap()
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}
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fn parse_input(input: &str) -> Vec<(u64, Vec<u64>)> {
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input
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.lines()
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.filter(|line| !line.is_empty())
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.map(|line| {
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let split_line = line.split_once(": ").unwrap();
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(
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split_line.0.parse().unwrap(),
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split_line
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.1
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.split_whitespace()
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.map(|s| s.parse().unwrap())
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.rev()
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.collect(),
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)
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})
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.collect()
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}
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fn is_valid(
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data: &mut Vec<u64>,
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acc: u64,
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target: u64,
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operators: &Vec<&fn(u64, u64) -> u64>,
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) -> bool {
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if data.is_empty() {
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return target == acc;
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}
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if acc > target {
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return false;
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}
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let old = data.pop().unwrap();
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for operator in operators {
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if is_valid(data, operator(acc, old), target, operators) {
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return true;
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}
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}
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data.push(old);
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false
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}
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fn sum_valid(
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calibration_data: &Vec<(u64, Vec<u64>)>,
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operators: &Vec<&fn(u64, u64) -> u64>,
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) -> u64 {
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let mut sum_valid = 0;
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let calibration_data = calibration_data.clone();
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for calibration in calibration_data {
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let mut x = calibration.1;
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let acc = x.pop().unwrap();
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if is_valid(&mut x, acc, calibration.0, operators) {
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sum_valid += calibration.0;
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}
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}
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sum_valid
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}
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fn part_1(input: &Vec<(u64, Vec<u64>)>) -> u64 {
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let valid_operators = vec![&(add as fn(u64, u64) -> u64), &(mul as fn(u64, u64) -> u64)];
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sum_valid(input, &valid_operators)
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}
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fn part_2(input: &Vec<(u64, Vec<u64>)>) -> u64 {
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let valid_operators = vec![
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&(add as fn(u64, u64) -> u64),
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&(mul as fn(u64, u64) -> u64),
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&(concat as fn(u64, u64) -> u64),
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];
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sum_valid(input, &valid_operators)
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}
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fn main() {
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let args: Vec<String> = env::args().collect();
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for arg in args.iter().skip(1) {
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let input = read_input(&arg);
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let calibration_data = parse_input(&input);
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println!("[{}]", &arg);
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println!("\t[Part 1] => Answer is '{}'.", part_1(&calibration_data));
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println!("\t[Part 2] => Answer is '{}'.", part_2(&calibration_data));
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}
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}
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