aoc/year2016/
day08.rs

1//! # Two-Factor Authentication
2//!
3//! The pixels are sparse enough that's it efficient to store them as [`Point`] objects and
4//! manipulate individually. Pixels don't overlap so we can use a vec instead of a set to store
5//! distinct points without overcounting.
6//!
7//! [`Point`]: crate::util::point
8use crate::util::grid::*;
9use crate::util::iter::*;
10use crate::util::parse::*;
11use crate::util::point::*;
12
13pub fn parse(input: &str) -> Vec<Point> {
14    let amounts = input.iter_signed::<i32>().chunk::<2>();
15    let mut points = Vec::new();
16
17    for (line, [a, b]) in input.lines().zip(amounts) {
18        if line.starts_with("rect") {
19            for x in 0..a {
20                for y in 0..b {
21                    points.push(Point::new(x, y));
22                }
23            }
24        } else if line.starts_with("rotate row") {
25            for point in &mut points {
26                if point.y == a {
27                    point.x = (point.x + b) % 50;
28                }
29            }
30        } else {
31            for point in &mut points {
32                if point.x == a {
33                    point.y = (point.y + b) % 6;
34                }
35            }
36        }
37    }
38
39    points
40}
41
42pub fn part1(input: &[Point]) -> usize {
43    input.len()
44}
45
46pub fn part2(input: &[Point]) -> String {
47    let mut grid = Grid::new(50, 6, '.');
48
49    (0..6).for_each(|y| grid[Point::new(0, y)] = '\n');
50    input.iter().for_each(|&p| grid[p + RIGHT] = '#');
51
52    grid.bytes.iter().collect()
53}
aoc/year2016/day08.rs

aoc/year2016/
day08.rs
