diff options
Diffstat (limited to '2022/rust')
-rw-r--r-- | 2022/rust/Cargo.toml | 2 | ||||
-rw-r--r-- | 2022/rust/day06/Cargo.toml | 8 | ||||
-rw-r--r-- | 2022/rust/day06/src/main.rs | 51 |
3 files changed, 60 insertions, 1 deletions
diff --git a/2022/rust/Cargo.toml b/2022/rust/Cargo.toml index e127354..4e87017 100644 --- a/2022/rust/Cargo.toml +++ b/2022/rust/Cargo.toml @@ -5,7 +5,7 @@ members = [ "day03", "day04", "day05", -# "day06", + "day06", # "day07", # "day08", # "day09", diff --git a/2022/rust/day06/Cargo.toml b/2022/rust/day06/Cargo.toml new file mode 100644 index 0000000..cd279fb --- /dev/null +++ b/2022/rust/day06/Cargo.toml @@ -0,0 +1,8 @@ +[package] +name = "day06" +version = "0.1.0" +edition = "2021" + +[dependencies] +aoc = { path = "../../../common/rust/aoc" } +anyhow = "1.0" diff --git a/2022/rust/day06/src/main.rs b/2022/rust/day06/src/main.rs new file mode 100644 index 0000000..d7bae65 --- /dev/null +++ b/2022/rust/day06/src/main.rs @@ -0,0 +1,51 @@ +use { + anyhow::{ + anyhow, + Context, + Result, + }, + std::{ + env::args, + fs::read_to_string, + path::Path, + }, +}; + +fn read_input<T: AsRef<Path>>(filename: T) -> Result<String> { + read_to_string(filename).context("Could not read {filename}") +} + +fn find_sequence(input: &str, len: usize) -> Option<usize> { + input.as_bytes().windows(len).enumerate().find_map(|(pos, win)| { + for i in 0..len { + if win[(i + 1)..].contains(&win[i]) { + return None + } + } + Some(pos + len) + }) +} + +fn part1(input: &str) -> Result<usize> { + find_sequence(input, 4).ok_or_else(|| anyhow!("No match found")) +} + +fn part2(input: &str) -> Result<usize> { + find_sequence(input, 14).ok_or_else(|| anyhow!("No match found")) +} + +fn main() -> Result<()> { + let ( do_part_1, do_part_2 ) = aoc::do_parts(); + + let filename = args().nth(1).ok_or_else(|| anyhow!("Missing input filename"))?; + let input = read_input(filename).context("Could not read input")?; + if do_part_1 { + let solution = part1(&input).context("No solution for part 1")?; + println!("Part1, solution found to be: {}", solution); + } + if do_part_2 { + let solution = part2(&input).context("No solution for part 2")?; + println!("Part2, solution found to be: {}", solution); + } + Ok(()) +} |