Table of content

What is this :grey_question:

The rules of the game are explained in my original post.

26th Challenge

Challenge

I have never part taken in Advent of Code. This year I might. To get used to the idea I’m solving last year’s second challenge. Solve AoC day 2 2020.

Solution :white_check_mark: 

	fn main() {
	    let answer = INPUT.lines()
	        .filter(|&x| check_line(x))
	        .count();

	    println!("{}",answer);
	}

	fn check_line(line:&str) -> bool {

	    let mut s:Vec<&str> = line
	        .split(' ')
	        .collect();

	    let range = s
	        .remove(0)
	        .split_once('-')
	        .unwrap();

	    let min:usize = range
	        .0
	        .parse()
	        .unwrap();

	    let max:usize = range
	        .1
	        .parse()
	        .unwrap();

	    let letter = s
	        .remove(0)
	        .trim_end_matches(":")
	        .chars()
	        .nth(0)
	        .unwrap();

	    let password = s.remove(0);

	    let num = password
	        .chars()
	        .filter(|c| c.eq(&letter))
	        .count();


	    num >= min && num <= max

	}

	const INPUT:&str = "1-3 a: abcde
	1-3 b: cdefg
	2-9 c: ccccccccc";

To see the full source see github and see the live demo in playground.