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pub fn part1() -> anyhow::Result<i64> {
let mut total = 0;
for line in data_lines!()? {
let mut open = vec![];
for c in line.chars() {
match c {
'{' | '(' | '[' | '<' => {
open.push(c);
}
'}' | ')' | ']' | '>' => {
let c_open = open.pop();
if let Some(c_open) = c_open {
let expected = match c_open {
'{' => '}',
'(' => ')',
'[' => ']',
'<' => '>',
_ => unreachable!(),
};
if c != expected {
total += match c {
'}' => 1197,
')' => 3,
']' => 57,
'>' => 25137,
_ => unreachable!(),
};
break;
}
} else {
break;
}
}
_ => break,
}
}
}
Ok(total)
}
pub fn part2() -> anyhow::Result<i64> {
let mut scores = vec![];
for line in data_lines!()? {
let mut open = vec![];
let mut skip = false;
for c in line.chars() {
match c {
'{' | '(' | '[' | '<' => {
open.push(c);
}
'}' | ')' | ']' | '>' => {
let c_open = open.pop();
if let Some(c_open) = c_open {
let expected = match c_open {
'{' => '}',
'(' => ')',
'[' => ']',
'<' => '>',
_ => unreachable!(),
};
if c != expected {
skip = true;
break;
}
} else {
skip = true;
break;
}
}
_ => {
skip = true;
break;
}
}
}
if !skip {
scores.push(open.iter().rev().fold(0, |acc, c| {
acc * 5
+ match c {
'(' => 1,
'[' => 2,
'{' => 3,
'<' => 4,
_ => unreachable!(),
}
}));
}
}
scores.sort_unstable();
Ok(scores[scores.len() / 2])
}
#[test]
fn test() {
assert_eq!(part1().unwrap(), 166191);
assert_eq!(part2().unwrap(), 1152088313);
}
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