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#![allow(dead_code)]
#![allow(unused_variables)]
use advent_of_code::prelude::*;
#[derive(Debug, Clone)]
pub struct MapRange {
dst_start: i64,
src_start: i64,
len: i64,
}
impl MapRange {
fn map(&self, n: i64) -> Option<i64> {
if n >= self.src_start && n < self.src_start + self.len {
Some(self.dst_start + (n - self.src_start))
} else {
None
}
}
fn src_range(&self) -> std::ops::RangeInclusive<i64> {
self.src_start..=(self.src_start + self.len - 1)
}
fn dst_range(&self) -> std::ops::RangeInclusive<i64> {
self.dst_start..=(self.src_start + self.len - 1)
}
}
#[derive(Debug, Clone)]
pub struct Map {
ranges: Vec<MapRange>,
}
impl Map {
fn map(&self, n: i64) -> i64 {
for range in &self.ranges {
if let Some(mapped) = range.map(n) {
return mapped;
}
}
n
}
fn map_range(
&self,
range: std::ops::RangeInclusive<i64>,
) -> Vec<std::ops::RangeInclusive<i64>> {
let mut ranges = vec![range];
for map_range in &self.ranges {
let mut new_ranges = vec![];
for range in ranges {
new_ranges.extend(
split_range(range, map_range.src_range()).into_iter(),
);
}
ranges = new_ranges;
}
ranges
.into_iter()
.map(|range| self.map(*range.start())..=self.map(*range.end()))
.collect()
}
}
#[derive(Debug, Clone)]
pub struct Almanac {
seeds: Vec<i64>,
maps: Vec<Map>,
}
impl Almanac {
fn location(&self, mut n: i64) -> i64 {
for map in &self.maps {
n = map.map(n);
}
n
}
}
fn split_range(
a: std::ops::RangeInclusive<i64>,
b: std::ops::RangeInclusive<i64>,
) -> Vec<std::ops::RangeInclusive<i64>> {
if a.start() > b.end() {
vec![a]
} else if a.start() < b.start() {
if a.end() < b.start() {
vec![a]
} else if a.end() <= b.end() {
vec![*a.start()..=(*b.start() - 1), *b.start()..=*a.end()]
} else {
vec![
*a.start()..=(*b.start() - 1),
b.clone(),
(*b.end() + 1)..=*a.end(),
]
}
} else if a.end() <= b.end() {
vec![a]
} else {
vec![*a.start()..=*b.end(), (*b.end() + 1)..=*a.end()]
}
}
pub fn parse(fh: File) -> Result<Almanac> {
let mut lines = parse::raw_lines(fh).fuse();
let seeds = lines.next().unwrap();
let seeds: Vec<i64> = seeds
.split(": ")
.nth(1)
.unwrap()
.split_whitespace()
.map(|s| s.parse().unwrap())
.collect();
lines.next().unwrap();
let mut maps = vec![];
while lines.next().is_some() {
let mut ranges = vec![];
for line in lines.by_ref() {
if line.is_empty() {
break;
}
let parts: Vec<i64> = line
.split_whitespace()
.map(|s| s.parse().unwrap())
.collect();
ranges.push(MapRange {
dst_start: parts[0],
src_start: parts[1],
len: parts[2],
})
}
maps.push(Map { ranges })
}
Ok(Almanac { seeds, maps })
}
pub fn part1(almanac: Almanac) -> Result<i64> {
Ok(almanac
.seeds
.iter()
.copied()
.map(|n| almanac.location(n))
.min()
.unwrap())
}
pub fn part2(almanac: Almanac) -> Result<i64> {
let mut tests = vec![];
for seed_range in almanac.seeds.chunks(2) {
#[allow(clippy::single_range_in_vec_init)]
let mut seed_ranges =
vec![seed_range[0]..=(seed_range[0] + seed_range[1] - 1)];
for map in &almanac.maps {
seed_ranges = seed_ranges
.into_iter()
.flat_map(|range| map.map_range(range))
.collect();
}
tests.extend(seed_ranges.into_iter().map(|range| *range.start()));
}
Ok(tests.into_iter().min().unwrap())
}
#[test]
fn test() {
assert_eq!(
part1(parse(parse::data(2023, 5).unwrap()).unwrap()).unwrap(),
173706076
);
assert_eq!(
part2(parse(parse::data(2023, 5).unwrap()).unwrap()).unwrap(),
11611182
);
}
|
