75 lines
2.0 KiB
Rust
75 lines
2.0 KiB
Rust
use aoc_runner_derive::aoc;
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use itertools::Itertools;
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use std::io::BufRead;
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// PROBLEM 1 solution
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#[aoc(day6, part1)]
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fn part1(input: &[u8]) -> u64 {
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let s = input.lines().next().unwrap().unwrap();
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s.as_bytes()
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.windows(4)
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.enumerate()
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.find_map(|(i, window)| {
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if window[1..4].iter().all(|c| *c != window[0])
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&& window[2..4].iter().all(|c| *c != window[1])
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&& window[2] != window[3]
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{
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println!(
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"Unique window: {:?} at {}",
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window.iter().map(|c| *c as char).collect_vec(),
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i
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);
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Some(i + 4)
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} else {
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None
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}
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})
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.unwrap() as u64
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}
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// PROBLEM 2 solution
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#[aoc(day6, part2)]
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fn part2(input: &[u8]) -> u64 {
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let s = input.lines().next().unwrap().unwrap();
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let size = 14;
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s.as_bytes()
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.windows(size)
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.enumerate()
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.find_map(|(i, window)| {
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for i in 1..size {
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let shifted = &window[i..];
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if shifted.iter().enumerate().any(|(j, c)| *c == window[j]) {
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return None;
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}
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}
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return Some(i + 14);
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})
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.unwrap() as u64
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}
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#[cfg(test)]
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mod tests {
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use crate::day6::*;
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const EXAMPLE1: &[u8] = b"bvwbjplbgvbhsrlpgdmjqwftvncz";
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const EXAMPLE2: &[u8] = b"nppdvjthqldpwncqszvftbrmjlhg";
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const EXAMPLE3: &[u8] = b"nznrnfrfntjfmvfwmzdfjlvtqnbhcprsg";
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const EXAMPLE4: &[u8] = b"zcfzfwzzqfrljwzlrfnpqdbhtmscgvjw";
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#[test]
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fn problem1_example() {
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assert_eq!(part1(EXAMPLE1), 5);
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assert_eq!(part1(EXAMPLE2), 6);
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assert_eq!(part1(EXAMPLE3), 10);
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assert_eq!(part1(EXAMPLE4), 11);
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}
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#[test]
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fn problem2_example() {
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assert_eq!(part2(EXAMPLE1), 23);
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assert_eq!(part2(EXAMPLE2), 23);
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assert_eq!(part2(EXAMPLE3), 29);
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assert_eq!(part2(EXAMPLE4), 26);
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}
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}
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