From 1d8de23da83a93e7960bdcea702c9cd3d082b5c5 Mon Sep 17 00:00:00 2001 From: June McEnroe Date: Mon, 5 Dec 2016 21:47:56 -0500 Subject: Day 5 part 2 --- src/bin/day05.rs | 38 +++++++++++++++++++++++++++++++++++--- 1 file 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")); } -- cgit 1.4.1