(2015, 11) => year_2015::day11::run("vzbxkghb"),

use common::sfy::Sfy;

use fancy_regex::*;

pub fn run(input: &str) {

println!("pro-tip: compile with --release!");

let part1 = solve(input);

println!("part 1: {}", part1);

assert_eq!(part1, "vzbxxyzz");

let part2 = solve("vzbxxyzz");

println!("part 2: {}", part2);

assert_eq!(part2, "vzcaabcc");

fn solve(input: &str) -> String {

// loop until we find a string which is valid

let len = input.len();

let mut s = Vec::from(input.as_bytes());

next(&mut s, len - 1);

let re = Regex::new(r"(.)\1.*(.)\2").unwrap();

while !valid(&s, &re) {

next(&mut s, len - 1);

}

return s.sfy();

fn next(input: &mut [u8], offset: usize) {

if input[offset] == b'z' {

input[offset] = b'a';

next(input, offset - 1);

} else {

input[offset] = input[offset] + 1;

if (input[offset] == b'i') || (input[offset] == b'o') || (input[offset] == b'l') {

// mini-optimization

input[offset] = input[offset] + 1;

for i in (offset + 1)..input.len() {

input[i] = b'a';

}

}

}

fn valid(input: &[u8], re: &Regex) -> bool {

// use a helper function to find a straight of 3 letters

if !has_straight(&input) {

return false;

}

// use a a loop to check if input contains i, o or l.

for i in input.iter() {

if (*i == b'i') || (*i == b'o') || (*i == b'l') {

return false;

}

}

// use regexp to check for non-overlapping pairs

if !re.is_match(&input.sfy()).unwrap() {

return false;

}

return true;

fn has_straight(input: &[u8]) -> bool {

for i in 0..input.len() - 2 {

if (input[i] == input[i + 1] - 1) && (input[i] == input[i + 2] - 2) {

return true;

}

}

return false;

pub mod day11;