108 lines
3 KiB
Rust
108 lines
3 KiB
Rust
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#![feature(array_windows)]
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use regex_lite::Regex;
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pub const INPUT: &str = include_str!("./input.txt");
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type Input = &'static str;
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fn parse_input(input: &'static str) -> Input {
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input
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}
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pub fn main() {
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let input = parse_input(INPUT);
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println!("Part 1: {}", part_1(&input));
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println!("Part 2: {}", part_2(&input));
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}
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fn part_1(input: &Input) -> usize {
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const PATTERN: &str = r"mul\((\d{1,3})\,(\d{1,3})\)";
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let regex = Regex::new(PATTERN).expect("I fucked up the regex");
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assert!(regex.is_match(INPUT));
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let mut sum = 0;
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for r#match in regex.captures_iter(input) {
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let first = r#match
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.get(1)
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.expect("Missing first number")
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.as_str()
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.parse::<usize>()
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.expect("Failed to parse first number:");
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let second = r#match
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.get(2)
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.expect("Missing second number")
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.as_str()
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.parse::<usize>()
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.expect("Failed to parse second number:");
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sum += first * second;
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}
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sum
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}
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fn part_2(input: &Input) -> usize {
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const PATTERN: &str = r"mul\((\d{1,3})\,(\d{1,3})\)|do\(\)|don't\(\)";
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let regex = Regex::new(PATTERN).expect("I fucked up the regex");
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assert!(regex.is_match(INPUT));
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let mut sum = 0;
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let mut enabled = true;
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for r#match in regex.captures_iter(input) {
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match r#match.get(0).unwrap().as_str() {
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"do()" => enabled = true,
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"don't()" => enabled = false,
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_ if enabled => {
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let first = r#match
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.get(1)
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.expect("Missing first number")
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.as_str()
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.parse::<usize>()
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.expect("Failed to parse first number:");
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let second = r#match
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.get(2)
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.expect("Missing second number")
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.as_str()
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.parse::<usize>()
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.expect("Failed to parse second number:");
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sum += first * second;
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}
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_ => {}
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}
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}
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sum
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}
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#[cfg(test)]
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mod tests {
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use crate::parse_input;
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const SAMPLE_INPUT_1: &str =
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r#"xmul(2,4)%&mul[3,7]!@^do_not_mul(5,5)+mul(32,64]then(mul(11,8)mul(8,5))"#;
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const SAMPLE_INPUT_2: &str =
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r#"xmul(2,4)&mul[3,7]!^don't()_mul(5,5)+mul(32,64](mul(11,8)undo()?mul(8,5))"#;
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#[test]
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fn test_part_1_with_sample_solution() {
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let input = parse_input(SAMPLE_INPUT_1);
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assert_eq!(super::part_1(&input), 161)
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}
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#[test]
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fn test_part_1_with_solution() {
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let input = parse_input(super::INPUT);
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assert_eq!(super::part_1(&input), 173529487);
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}
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#[test]
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fn test_part_2_with_sample_solution() {
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let input = parse_input(SAMPLE_INPUT_2);
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assert_eq!(super::part_2(&input), 48)
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}
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#[test]
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fn test_part_2_with_solution() {
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let input = parse_input(super::INPUT);
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assert_eq!(super::part_2(&input), 99532691);
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}
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}
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