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2022 rust day 15

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This commit is contained in:
Maciej Jur 2022-12-15 19:26:41 +01:00
parent 7d42c79ecd
commit 3586380a4e
1 changed files with 32 additions and 20 deletions
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52
2022/rust/src/solutions/day15.rs
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@ -9,7 +9,7 @@ pub fn run() -> () {
println!("Day 15"); println!("Day 15");
println!("Part 1: {}", solve1::<2000000>(&data)); println!("Part 1: {}", solve1::<2000000>(&data));
println!("Part 2: {}", solve2(&data)); println!("Part 2: {}", solve2::<4000000>(&data));
} }
@ -41,16 +41,6 @@ fn range_for_row((r, c): (isize, isize), range: usize, row: isize) -> Option<Ran
} }
} }
fn find_col_bounds(data: &Data) -> (isize, isize) {
data.iter()
.fold((0, 0), |acc, &(sensor, beacon)| {
(
acc.0.min(sensor.1.min(beacon.1)),
acc.1.max(sensor.1.max(beacon.1)),
)
})
}
fn merge_ranges(ranges: &Vec<Range>) -> Vec<Range> { fn merge_ranges(ranges: &Vec<Range>) -> Vec<Range> {
let mut ranges = ranges.clone(); let mut ranges = ranges.clone();
ranges.sort_by(|r1, r2| r1.start().cmp(&r2.start())); ranges.sort_by(|r1, r2| r1.start().cmp(&r2.start()));
@ -58,7 +48,7 @@ fn merge_ranges(ranges: &Vec<Range>) -> Vec<Range> {
ranges.next() ranges.next()
.map(|first| ranges .map(|first| ranges
.fold(vec![first], |mut acc, next| { .fold(vec![first], |mut acc, next| {
match next.start() <= acc.last().unwrap().end() { match next.start() - 1 <= *acc.last().unwrap().end() {
true => { true => {
let prev = acc.pop().unwrap(); let prev = acc.pop().unwrap();
let merged_l = *next.start().min(prev.start()); let merged_l = *next.start().min(prev.start());
@ -72,17 +62,17 @@ fn merge_ranges(ranges: &Vec<Range>) -> Vec<Range> {
.unwrap() .unwrap()
} }
fn solve1<const row: isize>(data: &Data) -> usize { fn solve1<const ROW: isize>(data: &Data) -> usize {
let ranges = find_ranges(data); let ranges = find_ranges(data);
let occupied = data.iter() let occupied = data.iter()
.fold(HashSet::new(), |mut acc, (a, b)| { .fold(HashSet::new(), |mut acc, (a, b)| {
if a.0 == row { acc.insert(a); } if a.0 == ROW { acc.insert(a); }
if b.0 == row { acc.insert(b); } if b.0 == ROW { acc.insert(b); }
acc acc
}); });
let ranges = ranges.iter() let ranges = ranges.iter()
.filter_map(|(&point, &range)| range_for_row(point, range, row)) .filter_map(|(&point, &range)| range_for_row(point, range, ROW))
.collect::<Vec<_>>(); .collect::<Vec<_>>();
let sum = merge_ranges(&ranges) let sum = merge_ranges(&ranges)
@ -93,8 +83,31 @@ fn solve1<const row: isize>(data: &Data) -> usize {
sum - occupied.len() sum - occupied.len()
} }
fn solve2(_data: &Data) -> i32 { fn solve2<const SPACE: isize>(data: &Data) -> isize {
2 let ranges = find_ranges(data);
let accepted_cols = 0..=SPACE;
(0..SPACE).into_iter()
.flat_map(|cur_row| {
let ranges = ranges.iter()
.filter_map(|(&point, &range)| range_for_row(point, range, cur_row))
.collect::<Vec<_>>();
let mut ranges = merge_ranges(&ranges).into_iter();
let spots = ranges.next()
.map(|first| ranges
.fold((vec![], first), |(mut acc, prev), next| {
match prev.end() + 2 == *next.start() && accepted_cols.contains(&(prev.end() + 1)) {
true => {
acc.push(prev.end() + 1);
(acc, next)
}
false => (acc, next)
}
}))
.unwrap().0;
spots.first().map(|&col| col * 4000000 + cur_row)
})
.next().unwrap()
} }
@ -150,7 +163,6 @@ mod tests {
#[test] #[test]
fn part2() { fn part2() {
let data = parse_data(DATA); assert_eq!(56000011, solve2::<20>(&parse_data(DATA)));
assert_eq!(56000011, solve2(&data));
} }
} }