Advent of Code solutions
Day 5
+88
-7
+16
-1
utils/src/range.rs
+16
-1
utils/src/range.rs
···
51
51
/// ```
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52
///
53
53
pub fn contains_range(&self, other: &Self) -> bool {
54
-
self.start <= other.start && other.end < self.end
54
+
self.start <= other.start && other.end <= self.end
55
+
}
56
+
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+
/// Merge this range with another. If the ranges do not intersect, [None] is returned.
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+
pub fn merge(&self, other: &Self) -> Option<Self> {
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+
if self.contains_range(other) {
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+
Some(*self)
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+
} else if other.contains_range(self) {
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+
Some(*other)
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+
} else if self.contains(&other.start) || self.end == other.start {
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+
Some(Self::new(self.start, other.end))
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+
} else if self.contains(&other.end) || other.end == self.start {
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+
Some(Self::new(other.start, self.end))
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+
} else {
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+
None
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+
}
55
70
}
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71
57
72
/// Split the range at the given value.
+50
-6
years/2025/src/day_5.rs
+50
-6
years/2025/src/day_5.rs
···
1
-
2
1
use advent_core::{Day, day_stuff, ex_for_day};
2
+
use utils::range::BetterRange;
3
3
4
4
pub struct Day5;
5
5
6
6
impl Day for Day5 {
7
+
day_stuff!(5, "3", "14", (Vec<BetterRange<usize>>, Vec<usize>));
7
8
8
-
day_stuff!(5, "", "");
9
+
fn part_1((ranges, ids): Self::Input) -> Option<String> {
10
+
let ans = ids
11
+
.into_iter()
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+
.filter(|id| ranges.iter().any(|range| range.contains(id)))
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+
.count();
9
14
10
-
fn part_1(_input: Self::Input) -> Option<String> {
11
-
None
15
+
Some(ans.to_string())
12
16
}
13
17
14
-
fn part_2(_input: Self::Input) -> Option<String> {
15
-
None
18
+
fn part_2((mut ranges, _): Self::Input) -> Option<String> {
19
+
ranges.sort_by(|a, b| a.start.cmp(&b.start).then(a.end.cmp(&b.end)));
20
+
21
+
let mut new_ranges = Vec::with_capacity(ranges.len());
22
+
23
+
for range in ranges {
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+
let mut merged = false;
25
+
26
+
for new_range in new_ranges.iter_mut() {
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+
if let Some(merged_range) = range.merge(new_range) {
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+
merged = true;
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+
*new_range = merged_range;
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+
break;
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+
}
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+
}
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+
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+
if !merged {
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+
new_ranges.push(range);
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+
}
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+
}
38
+
39
+
let ans = new_ranges
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+
.into_iter()
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+
.map(|range| range.end - range.start)
42
+
.sum::<usize>();
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+
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+
Some(ans.to_string())
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+
}
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+
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+
fn parse_input(input: &str) -> Self::Input {
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+
let (ranges, ids) = input.split_once("\n\n").unwrap();
49
+
50
+
(
51
+
ranges
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+
.lines()
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+
.map(|l| {
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+
let (lower, upper) = l.split_once('-').unwrap();
55
+
BetterRange::new(lower.parse().unwrap(), upper.parse::<usize>().unwrap() + 1)
56
+
})
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+
.collect(),
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+
ids.lines().map(|l| l.parse().unwrap()).collect(),
59
+
)
16
60
}
17
61
}
+11
years/2025/src/examples/day_5/1.txt
+11
years/2025/src/examples/day_5/1.txt