advent-of-code/2022/rust/src/day6.rs

58 lines
1.1 KiB
Rust

mod common;
use std::collections::HashSet;
type Input = str;
type Result = usize;
fn part1(input: &Input) -> Result {
let c: Vec<char> = input.chars().collect();
for i in 3.. {
if c[i] != c[i - 1]
&& c[i] != c[i - 2]
&& c[i] != c[i - 3]
&& c[i - 1] != c[i - 2]
&& c[i - 1] != c[i - 3]
&& c[i - 2] != c[i - 3]
{
return i + 1;
}
}
0
}
fn part2(input: &Input) -> Result {
let c: Vec<char> = input.chars().collect();
for i in 13..c.len() {
let mut s: HashSet<char> = HashSet::new();
for j in i - 13..=i {
s.insert(c[j]);
}
if s.len() == 14 {
return i + 1;
}
}
0
}
fn main() {
let input_text = common::day_input(6);
common::show_answers(&part1(&input_text), &part2(&input_text))
}
#[cfg(test)]
mod tests {
use super::*;
const TEST_INPUT: &str = "mjqjpqmgbljsphdztnvjfqwrcgsmlb";
#[test]
fn test() {
let input = TEST_INPUT;
assert_eq!(part1(input), 7);
assert_eq!(part2(input), 19);
}
}