AoC23/src/day01.rs

81 lines
1.8 KiB
Rust
Raw Normal View History

2023-12-01 05:35:37 +00:00
use regex::Regex;
pub fn run() {
let input = include_str!("../input/day1.txt");
// let input = r#"1abc2
// pqr3stu8vwx
// a1b2c3d4e5f
// treb7uchet"#;
// let input = r#"two1nine
// eightwothree
// abcone2threexyz
// xtwone3four
// 4nineeightseven2
// zoneight234
// 7pqrstsixteen"#;
// let sum: u32 = input
// .lines()
// .filter(|s| !s.is_empty())
// .map(|s| find_digits(s))
// .sum();
// dbg!(sum);
dbg!(find_digits_part2("gdgj3f"));
let sum2 = input
.lines()
.filter(|s| !s.is_empty())
.map(|s| find_digits_part2(s))
.sum::<u32>();
dbg!(sum2);
}
fn find_digits(s: &str) -> u32 {
let first = s
.chars()
.nth(s.find(|c: char| c.is_ascii_digit()).unwrap())
.unwrap()
.to_digit(10)
.unwrap();
let last = s
.chars()
.nth(s.rfind(|c: char| c.is_ascii_digit()).unwrap())
.unwrap()
.to_digit(10)
.unwrap();
first * 10 + last
}
fn find_digits_part2(s: &str) -> u32 {
let re = Regex::new("^([1-9]|one|two|three|four|five|six|seven|eight|nine)").unwrap();
let mut s = s.to_owned();
let mut first: Option<u32> = None;
let mut last: Option<u32> = None;
while !s.is_empty() {
if let Some(m) = re.find(&s) {
last = Some(parse_digit(m.as_str()));
if first == None {
first = last;
}
}
s.remove(0);
}
return first.unwrap() * 10 + last.unwrap();
}
fn parse_digit(s: &str) -> u32 {
match s {
"one" => 1,
"two" => 2,
"three" => 3,
"four" => 4,
"five" => 5,
"six" => 6,
"seven" => 7,
"eight" => 8,
"nine" => 9,
_ => s.parse().unwrap(),
}
}