4 Commits

3 changed files with 134 additions and 11 deletions

View File

@@ -110,10 +110,15 @@ impl BluePrint {
if u32::from(best - got) >= ideal_from_now {
continue;
}
assert!(todo.len() <= 1_000_000, "Safety: got a todo list of len {}, best: {best}",
todo.len());
assert!(
todo.len() <= 1_000_000,
"Safety: got a todo list of len {}, best: {best}",
todo.len()
);
for (element, &costs) in self.costs.iter().enumerate() {
let Some(min_to_build) = self.until_buildable(costs, resources, machines) else { break };
let Some(min_to_build) = self.until_buildable(costs, resources, machines) else {
break;
};
// +1 because we need a turn to build
let built_after = min_to_build + 1;

View File

@@ -136,7 +136,9 @@ pub fn part1(input: &[u8]) -> Result<String> {
pub fn part2(input: &[u8]) -> Result<String> {
let monkeys = parse_input(input, parse_monkeys)?;
let Monkey::Operation(first, second, _) = &monkeys[&b"root"[..]] else { anyhow::bail!("root is a literal somehow")};
let Monkey::Operation(first, second, _) = &monkeys[&b"root"[..]] else {
anyhow::bail!("root is a literal somehow")
};
let result = match (evaluate2(&monkeys, first), evaluate2(&monkeys, second)) {
(Ok(_), Ok(_)) => anyhow::bail!("both arms succeeded"),

View File

@@ -128,14 +128,18 @@ fn parse_map(input: &[u8]) -> IResult<&[u8], (Map, Vec<Step>)> {
)(input)
}
fn find_starting_x(top_row: &[u8]) -> Result<usize> {
top_row
.iter()
.position(|&b| b == b'.')
.context("Could not find starting position")
}
pub fn part1(input: &[u8]) -> Result<String> {
let (map, steps) = parse_input(input, parse_map)?;
let mut dir = Direction::Right;
let mut y = 0;
let mut x = map[y]
.iter()
.position(|&b| b == b'.')
.context("Could not find starting position")?;
let mut x = find_starting_x(map[y])?;
for step in steps {
match step {
@@ -268,13 +272,125 @@ fn break_squares<'a>(map: &[&'a [u8]], side_length: usize) -> [(Map<'a>, usize,
}
pub fn part2(input: &[u8]) -> Result<String> {
let (map, _steps) = parse_input(input, parse_map)?;
let (map, steps) = parse_input(input, parse_map)?;
let side_length = side_length_of(&map);
let _squares = break_squares(&map, side_length);
let squares = break_squares(&map, side_length);
anyhow::bail!("not implemented")
let convert_coords = |square: usize, x: usize, y: usize| {
let offset_x = squares[square].1 * side_length + x + 1;
let offset_y = squares[square].2 * side_length + y + 1;
(offset_x, offset_y)
};
let mut current_square = 0;
let mut y = 0;
let mut x = find_starting_x(squares[current_square].0[y])?;
let mut dir = Direction::Right;
for step in steps {
match step {
Step::Left => dir = dir.turn_left(),
Step::Right => dir = dir.turn_right(),
Step::Forward(mut amount) => {
'outer: while amount > 0 {
let map = &squares[current_square].0;
let coord = match dir {
Direction::Up => {
while amount > 0 {
if y == 0 {
break;
} else if map[y - 1][x] == b'#' {
break 'outer;
} else {
y -= 1;
amount -= 1;
}
}
x
}
Direction::Down => {
while amount > 0 {
if y + 1 >= side_length {
break;
} else if map[y + 1][x] == b'#' {
break 'outer;
} else {
amount -= 1;
y += 1;
}
}
x
}
Direction::Left => {
while amount > 0 {
if x == 0 {
break;
} else if map[y][x - 1] == b'#' {
break 'outer;
} else {
x -= 1;
amount -= 1;
}
}
y
}
Direction::Right => {
while amount > 0 {
if x + 1 >= side_length {
break;
} else if map[y][x + 1] == b'#' {
break 'outer;
} else {
amount -= 1;
x += 1;
}
}
y
}
};
if amount > 0 {
let (new_dir, new_square, invert) =
TRANSITIONS[current_square][dir as usize];
let flipped_coord = if invert {
side_length - 1 - coord
} else {
coord
};
let (new_x, new_y) = match new_dir {
Direction::Up => (flipped_coord, side_length - 1),
Direction::Down => (flipped_coord, 0),
Direction::Left => (side_length - 1, flipped_coord),
Direction::Right => (0, flipped_coord),
};
if squares[new_square].0[new_y][new_x] == b'#' {
break 'outer;
}
x = new_x;
y = new_y;
current_square = new_square;
dir = new_dir;
amount -= 1;
}
}
}
}
}
let (real_x, real_y) = convert_coords(current_square, x, y);
Ok((1000 * real_y + 4 * real_x + dir as usize).to_string())
}
#[cfg(test)]