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#![allow(dead_code)]
#![allow(unused_variables)]
use advent_of_code::prelude::*;
fn print_elves(elves: &HashSet<(IRow, ICol)>) {
let min_row = elves.iter().map(|elf| elf.0).min().unwrap();
let max_row = elves.iter().map(|elf| elf.0).max().unwrap();
let min_col = elves.iter().map(|elf| elf.1).min().unwrap();
let max_col = elves.iter().map(|elf| elf.1).max().unwrap();
for row in (min_row.0..=max_row.0).map(IRow) {
for col in (min_col.0..=max_col.0).map(ICol) {
if elves.contains(&(row, col)) {
print!("#");
} else {
print!(".")
}
}
println!()
}
}
pub fn parse(fh: File) -> Result<HashSet<(IRow, ICol)>> {
let mut elves = HashSet::new();
for (row, line) in parse::raw_lines(fh).enumerate() {
for (col, c) in line.chars().enumerate() {
match c {
'#' => {
elves.insert((IRow(row as isize), ICol(col as isize)));
}
'.' => {}
_ => panic!("unexpected char {}", c),
}
}
}
Ok(elves)
}
fn neighbors(elf: (IRow, ICol)) -> Vec<(IRow, ICol)> {
vec![
(elf.0 - 1, elf.1 - 1),
(elf.0 - 1, elf.1),
(elf.0 - 1, elf.1 + 1),
(elf.0, elf.1 - 1),
(elf.0, elf.1 + 1),
(elf.0 + 1, elf.1 - 1),
(elf.0 + 1, elf.1),
(elf.0 + 1, elf.1 + 1),
]
}
pub fn part1(mut elves: HashSet<(IRow, ICol)>) -> Result<isize> {
let mut possible: VecDeque<(IRow, ICol)> = VecDeque::new();
possible.push_back((IRow(-1), ICol(0)));
possible.push_back((IRow(1), ICol(0)));
possible.push_back((IRow(0), ICol(-1)));
possible.push_back((IRow(0), ICol(1)));
for _ in 0..10 {
let mut moves: HashSet<((IRow, ICol), (IRow, ICol))> = HashSet::new();
for elf in &elves {
if neighbors(*elf)
.iter()
.all(|neighbor| !elves.contains(neighbor))
{
continue;
}
for diff in &possible {
let occupied = if diff.0 == IRow(0) {
elves.contains(&(elf.0 - 1, elf.1 + diff.1 .0))
|| elves.contains(&(elf.0, elf.1 + diff.1 .0))
|| elves.contains(&(elf.0 + 1, elf.1 + diff.1 .0))
} else {
elves.contains(&(elf.0 + diff.0 .0, elf.1 - 1))
|| elves.contains(&(elf.0 + diff.0 .0, elf.1))
|| elves.contains(&(elf.0 + diff.0 .0, elf.1 + 1))
};
if !occupied {
moves.insert((
*elf,
(elf.0 + diff.0 .0, elf.1 + diff.1 .0),
));
break;
}
}
}
let mut targets: HashMap<(IRow, ICol), usize> = HashMap::new();
for (from, to) in &moves {
*targets.entry(*to).or_default() += 1;
}
for (from, to) in &moves {
if targets.get(to).copied().unwrap_or(0) == 1 {
elves.remove(from);
elves.insert(*to);
}
}
let first = possible.pop_front().unwrap();
possible.push_back(first);
}
let min_row = elves.iter().map(|elf| elf.0).min().unwrap();
let max_row = elves.iter().map(|elf| elf.0).max().unwrap();
let min_col = elves.iter().map(|elf| elf.1).min().unwrap();
let max_col = elves.iter().map(|elf| elf.1).max().unwrap();
let area = (max_row.0 - min_row.0 + 1) * (max_col.0 - min_col.0 + 1);
Ok(area - elves.len() as isize)
}
pub fn part2(mut elves: HashSet<(IRow, ICol)>) -> Result<usize> {
let mut possible: VecDeque<(IRow, ICol)> = VecDeque::new();
possible.push_back((IRow(-1), ICol(0)));
possible.push_back((IRow(1), ICol(0)));
possible.push_back((IRow(0), ICol(-1)));
possible.push_back((IRow(0), ICol(1)));
let mut round = 0;
loop {
round += 1;
let mut moves: HashSet<((IRow, ICol), (IRow, ICol))> = HashSet::new();
for elf in &elves {
if neighbors(*elf)
.iter()
.all(|neighbor| !elves.contains(neighbor))
{
continue;
}
for diff in &possible {
let occupied = if diff.0 == IRow(0) {
elves.contains(&(elf.0 - 1, elf.1 + diff.1 .0))
|| elves.contains(&(elf.0, elf.1 + diff.1 .0))
|| elves.contains(&(elf.0 + 1, elf.1 + diff.1 .0))
} else {
elves.contains(&(elf.0 + diff.0 .0, elf.1 - 1))
|| elves.contains(&(elf.0 + diff.0 .0, elf.1))
|| elves.contains(&(elf.0 + diff.0 .0, elf.1 + 1))
};
if !occupied {
moves.insert((
*elf,
(elf.0 + diff.0 .0, elf.1 + diff.1 .0),
));
break;
}
}
}
let mut targets: HashMap<(IRow, ICol), usize> = HashMap::new();
for (from, to) in &moves {
*targets.entry(*to).or_default() += 1;
}
let mut moved = false;
for (from, to) in &moves {
if targets.get(to).copied().unwrap_or(0) == 1 {
elves.remove(from);
elves.insert(*to);
moved = true;
}
}
if !moved {
break;
}
let first = possible.pop_front().unwrap();
possible.push_back(first);
}
Ok(round)
}
#[test]
fn test() {
assert_eq!(
part1(parse(parse::data(2022, 23).unwrap()).unwrap()).unwrap(),
0
);
assert_eq!(
part2(parse(parse::data(2022, 23).unwrap()).unwrap()).unwrap(),
0
);
}
|
