1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
|
use std::collections::{BTreeSet, HashMap};
use crate::{Problem, Solution};
pub struct Day11;
impl Problem for Day11 {
const DAY: u8 = 11;
const INPUT: &'static str = include_str!("../input/day_11.txt");
}
impl Solution for Day11 {
type Answer1 = usize;
type Answer2 = usize;
fn part_1(input: &str) -> anyhow::Result<Self::Answer1> {
solve(input, 2)
}
fn part_2(input: &str) -> anyhow::Result<Self::Answer2> {
solve(input, 1000000)
}
}
fn solve(input: &str, rate: usize) -> anyhow::Result<usize> {
let mut graph: Graph = input.parse()?;
graph.expand(rate);
let mut nodes = graph.into_nodes();
let mut edges = HashMap::new();
while let Some(node) = nodes.pop_first() {
for other in nodes.iter() {
edges.insert((node, *other), node.dist(other));
}
}
Ok(edges.values().sum())
}
#[derive(Debug, Default, Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash)]
struct Node {
id: usize,
row: usize,
col: usize,
}
impl Node {
fn dist(&self, other: &Node) -> usize {
self.row.abs_diff(other.row) + self.col.abs_diff(other.col)
}
}
#[derive(Debug, Default)]
struct Graph {
inner: Vec<Vec<bool>>,
row_values: Vec<usize>,
col_values: Vec<usize>,
}
impl Graph {
fn rows(&self) -> usize {
self.inner.len()
}
fn cols(&self) -> usize {
self.inner.first().map(|v| v.len()).unwrap_or_default()
}
fn expand(&mut self, rate: usize) {
let mut rows = vec![false; self.rows()];
let mut cols = vec![false; self.cols()];
for row in 0..self.rows() {
for col in 0..self.cols() {
rows[row] = rows[row] || self.inner[row][col];
cols[col] = cols[col] || self.inner[row][col];
}
}
self.row_values = rows
.iter()
.map(|not_expanded| (!not_expanded).then_some(rate - 1).unwrap_or_default())
.collect();
self.col_values = cols
.iter()
.map(|not_expanded| (!not_expanded).then_some(rate - 1).unwrap_or_default())
.collect();
}
fn into_nodes(self) -> BTreeSet<Node> {
let mut nodes = BTreeSet::new();
let mut id = 0;
for (row, v) in self.inner.into_iter().enumerate() {
for (col, value) in v.into_iter().enumerate() {
if value {
id += 1;
nodes.insert(Node {
id,
row: row + self.row_values[0..row].iter().sum::<usize>(),
col: col + self.col_values[0..col].iter().sum::<usize>(),
});
}
}
}
nodes
}
}
impl std::str::FromStr for Graph {
type Err = std::convert::Infallible;
fn from_str(s: &str) -> Result<Self, Self::Err> {
Ok(Self {
inner: s
.lines()
.map(|s| s.chars().map(|c| c == '#').collect::<Vec<_>>())
.collect::<Vec<_>>(),
..Default::default()
})
}
}
#[cfg(test)]
mod tests {
use super::*;
const INPUT: &str = indoc::indoc! {"
...#......
.......#..
#.........
..........
......#...
.#........
.........#
..........
.......#..
#...#.....
"};
#[test]
fn test_part_1() -> anyhow::Result<()> {
Ok(assert_eq!(374, Day11::part_1(INPUT)?))
}
#[test]
fn test_part_2() -> anyhow::Result<()> {
Ok(assert_eq!(8410, solve(INPUT, 100)?))
}
}
|
