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author | June McEnroe <june@causal.agency> | 2016-12-05 21:47:56 -0500 |
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committer | June McEnroe <june@causal.agency> | 2020-11-22 00:14:24 -0500 |
commit | 1d8de23da83a93e7960bdcea702c9cd3d082b5c5 (patch) | |
tree | bbe637aad935e390c65d42a73106248a5771800c | |
parent | Day 5 (diff) | |
download | aoc-1d8de23da83a93e7960bdcea702c9cd3d082b5c5.tar.gz aoc-1d8de23da83a93e7960bdcea702c9cd3d082b5c5.zip |
Day 5 part 2
Diffstat (limited to '')
-rw-r--r-- | src/bin/day05.rs | 38 |
1 files changed, 35 insertions, 3 deletions
diff --git a/src/bin/day05.rs b/src/bin/day05.rs index a860e53..eefa3df 100644 --- a/src/bin/day05.rs +++ b/src/bin/day05.rs @@ -5,7 +5,7 @@ use std::io::{self, Read}; use crypto::digest::Digest; use crypto::md5::Md5; -fn solve(input: &str) -> String { +fn solve1(input: &str) -> String { let mut password = String::new(); let mut index = 0u64; @@ -25,15 +25,47 @@ fn solve(input: &str) -> String { password } +fn solve2(input: &str) -> String { + let mut password = [None; 8]; + let mut index = 0u64; + + while !password.iter().all(Option::is_some) { + let mut md5 = Md5::new(); + md5.input_str(input); + md5.input_str(&index.to_string()); + let digest = md5.result_str(); + + if &digest[0..5] == "00000" { + if let Some(pos @ 0 ... 7) = digest[5..6].parse().ok() { + password[pos] = password[pos].or(digest[6..7].chars().next()); + } + } + + index += 1; + } + + password.iter() + .cloned() + .map(Option::unwrap) + .collect() +} + fn main() { let mut input = String::new(); io::stdin().read_to_string(&mut input).unwrap(); - println!("Part 1: {}", solve(input.trim())); + println!("Part 1: {}", solve1(input.trim())); + println!("Part 2: {}", solve2(input.trim())); } #[test] #[ignore] fn part1() { - assert_eq!("18f47a30", solve("abc")); + assert_eq!("18f47a30", solve1("abc")); +} + +#[test] +#[ignore] +fn part2() { + assert_eq!("05ace8e3", solve2("abc")); } |