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extern crate advent_of_code_2017;
use advent_of_code_2017::*;
fn main() {
let args = AdventArgs::init();
let input = args.input[0].clone();
let mut used = 0;
let mut grid: Vec<Vec<bool>> = vec!(vec!(false; 128); 128);
for i in 0..128 {
let to_hash = format!("{}-{}", input, i);
let hash = knot_hash(&to_hash);
for (x1,c) in hash.chars().enumerate() {
let parsed = u32::from_str_radix(&c.to_string(), 16).unwrap();
used += parsed.count_ones();
for (x2,b) in format!("{:04b}",parsed).chars().enumerate() {
grid[i][4*x1+x2] = b == '1';
}
}
}
if args.part == 1 {
println!("{} is used", used);
} else {
let mut group_count = 0;
for start_y in 0..128 {
for start_x in 0..128 {
if grid[start_y][start_x] {
group_count += 1;
clear_group(&mut grid, Point{
x: start_x as i32,
y: start_y as i32
});
}
}
}
println!("{} groups", group_count);
}
}
fn clear_group(grid: &mut Vec<Vec<bool>>, point: Point) {
if point.x >= 0 && point.x < 128 && point.y >= 0 && point.y < 128 {
if grid[point.y as usize][point.x as usize] {
grid[point.y as usize][point.x as usize] = false;
clear_group(grid, point.up());
clear_group(grid, point.down());
clear_group(grid, point.left());
clear_group(grid, point.right());
}
}
}
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