2018: day02: part 2

This commit is contained in:
Antoine Martin 2019-11-15 15:18:36 +01:00
parent b4c1f36767
commit 0968951383

View file

@ -6,6 +6,7 @@ const INPUT: &str = include_str!("../input/day02.txt");
pub fn run() -> Result<()> { pub fn run() -> Result<()> {
println!("part 1: {}", part1(INPUT)?); println!("part 1: {}", part1(INPUT)?);
println!("part 2: {}", part2(INPUT)?);
Ok(()) Ok(())
} }
@ -32,6 +33,36 @@ fn part1(input: &str) -> Result<u32> {
Ok(twice * thrice) Ok(twice * thrice)
} }
fn part2(input: &str) -> Result<String> {
let lines = input.lines().collect::<Vec<&str>>();
for i in 0..lines.len() {
for j in (i + 1)..lines.len() {
let different = lines[i]
.chars()
.zip(lines[j].chars())
.filter(|tuple| tuple.0 != tuple.1)
.count();
if different == 1 {
return Ok(common_letters(lines[i], lines[j]));
}
}
}
Ok("".into())
}
fn common_letters(a: &str, b: &str) -> String {
a.chars()
.zip(b.chars())
.filter_map(|e| match e {
(a, b) if a == b => Some(a),
_ => None,
})
.collect()
}
#[cfg(test)] #[cfg(test)]
mod tests { mod tests {
use super::*; use super::*;
@ -54,4 +85,23 @@ ababab
fn part1_real() { fn part1_real() {
assert_eq!(part1(INPUT).unwrap(), 5750); assert_eq!(part1(INPUT).unwrap(), 5750);
} }
#[test]
fn part2_provided() {
let input = "abcde
fghij
klmno
pqrst
fguij
axcye
wvxyz
";
assert_eq!(part2(input).unwrap(), "fgij");
}
#[test]
fn part2_real() {
assert_eq!(part2(INPUT).unwrap(), "tzyvunogzariwkpcbdewmjhxi");
}
} }