diff options
Diffstat (limited to '2021/day10/src')
| -rw-r--r-- | 2021/day10/src/lib.rs | 191 |
1 files changed, 191 insertions, 0 deletions
diff --git a/2021/day10/src/lib.rs b/2021/day10/src/lib.rs new file mode 100644 index 0000000..6cf54ad --- /dev/null +++ b/2021/day10/src/lib.rs @@ -0,0 +1,191 @@ +use std::collections::VecDeque; +use std::str::FromStr; + +pub struct SyntaxLines { + lines: Vec<String>, +} + +impl FromStr for SyntaxLines { + type Err = (); + + fn from_str(input: &str) -> Result<Self, Self::Err> { + let lines: Vec<_> = input + .trim() + .split('\n') + .map(|x| x.to_owned()) + .collect::<Vec<String>>(); + + Ok(SyntaxLines { lines }) + } +} + +impl SyntaxLines { + pub fn part1(&self) -> u32 { + let mut result: u32 = 0; + + for line in &self.lines { + let mut qopen = VecDeque::new(); + let mut panic_char = ' '; + + for character in line.chars() { + match character { + c if character == '(' + || character == '[' + || character == '{' + || character == '<' => + { + qopen.push_back(c); + } + c if character == ')' + || character == ']' + || character == '}' + || character == '>' => + { + match qopen.pop_back() { + Some(bracket) => { + let mut error = false; + if c == ')' && bracket != '(' { + error = true; + } else if c == ']' && bracket != '[' { + error = true; + } else if c == '}' && bracket != '{' { + error = true; + } else if c == '>' && bracket != '<' { + error = true; + } + + if error { + panic_char = c; + } + } + None => panic!("Wtf?"), + }; + } + _ => {} + }; + + if panic_char != ' ' { + if panic_char == ')' { + result += 3; + } else if panic_char == ']' { + result += 57; + } else if panic_char == '}' { + result += 1197; + } else if panic_char == '>' { + result += 25137; + } + break; + } + } + } + + result + } + + pub fn part2(&self) -> u64 { + let mut scores = Vec::<u64>::new(); + + for line in &self.lines { + let mut qopen = VecDeque::new(); + let mut panic_char = ' '; + let mut result: u64 = 0; + + for character in line.chars() { + match character { + c if character == '(' + || character == '[' + || character == '{' + || character == '<' => + { + qopen.push_back(c); + } + c if character == ')' + || character == ']' + || character == '}' + || character == '>' => + { + match qopen.pop_back() { + Some(bracket) => { + let mut error = false; + if c == ')' && bracket != '(' { + error = true; + } else if c == ']' && bracket != '[' { + error = true; + } else if c == '}' && bracket != '{' { + error = true; + } else if c == '>' && bracket != '<' { + error = true; + } + + if error { + panic_char = c; + } + } + None => panic!("Wtf?"), + }; + } + _ => {} + }; + + if panic_char != ' ' { + break; + } + } + + if panic_char == ' ' { + while !qopen.is_empty() { + let v = qopen.pop_back().unwrap(); + result *= 5; + result += if v == '(' { + 1 + } else if v == '[' { + 2 + } else if v == '{' { + 3 + } else { + 4 + }; + } + scores.push(result); + } + } + + let middle = scores.len() / 2 as usize; + scores.sort(); + + scores[middle] + } +} + +#[cfg(test)] +mod tests { + use super::*; + + #[test] + fn test_example() { + let input: SyntaxLines = include_str!("../example.txt").parse().unwrap(); + let result = input.part1(); + assert_eq!(result, 26397); + } + + #[test] + fn test_example_part2() { + let input: SyntaxLines = include_str!("../example.txt").parse().unwrap(); + let result = input.part2(); + assert_eq!(result, 288957); + } + + #[test] + fn test_puzzle_input() { + let input: SyntaxLines = include_str!("../input.txt").parse().unwrap(); + let result = input.part1(); + assert_eq!(result, 392367); + } + + #[test] + fn test_puzzle_input_part2() { + let input: SyntaxLines = include_str!("../input.txt").parse().unwrap(); + let result = input.part2(); + assert_eq!(result, 2192104158); + } +} |