ktims/aoc2023
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Compare commits

base: ktims:5666aee5f2f3cf5e53c38fba7f75c04945bd6d6d
Branches Tags
ktims:main
..
compare: ktims:c797e874d5760b54024ddd1c13214bc06ac0ae5e
Branches Tags
ktims:main

No commits in common. "5666aee5f2f3cf5e53c38fba7f75c04945bd6d6d" and "c797e874d5760b54024ddd1c13214bc06ac0ae5e" have entirely different histories.
5666aee5f2 ... c797e874d5

4 changed files with 0 additions and 1591 deletions
Show Stats Expand all files Collapse all files

7
13/Cargo.lock generated
View File

@ -1,7 +0,0 @@
# This file is automatically @generated by Cargo.
# It is not intended for manual editing.
version = 3
[[package]]
name = "day13"
version = "0.1.0"

8
13/Cargo.toml
View File

@ -1,8 +0,0 @@
[package]
name = "day13"
version = "0.1.0"
edition = "2021"
# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
[dependencies]

1349
13/input
View File

File diff suppressed because it is too large Load Diff

227
13/src/main.rs
View File

@ -1,227 +0,0 @@
use std::fs::File;
use std::io::{BufRead, BufReader, Lines};
use std::ops::Index;
use std::time::Instant;
// BOILERPLATE
type InputIter = Lines<BufReader<File>>;
fn get_input() -> InputIter {
let f = File::open("input").unwrap();
let br = BufReader::new(f);
br.lines()
}
fn main() {
let start = Instant::now();
let ans1 = problem1(get_input());
let duration = start.elapsed();
println!("Problem 1 solution: {} [{}s]", ans1, duration.as_secs_f64());
let start = Instant::now();
let ans2 = problem2(get_input());
let duration = start.elapsed();
println!("Problem 2 solution: {} [{}s]", ans2, duration.as_secs_f64());
}
// PARSE
#[derive(Debug)]
struct Pattern {
mirrors: Vec<Vec<char>>,
}
impl Pattern {
fn width(&self) -> usize {
self.mirrors[0].len()
}
fn height(&self) -> usize {
self.mirrors.len()
}
fn col(&self, idx: usize) -> Vec<char> {
self.mirrors.iter().map(|row| row[idx]).collect()
}
fn find_horizontal_reflection(&self) -> Option<usize> {
(1..self.height()).find(|idx| self.is_horizontal_reflection(*idx))
}
fn is_horizontal_reflection(&self, idx: usize) -> bool {
let row_pairs = std::cmp::min(idx, self.height() - idx);
(0..row_pairs).all(|offset| self.mirrors[idx - offset - 1] == self.mirrors[idx + offset])
}
fn find_vertical_reflection(&self) -> Option<usize> {
(1..self.width()).find(|idx| self.is_vertical_reflection(*idx))
}
fn is_vertical_reflection(&self, idx: usize) -> bool {
let col_pairs = std::cmp::min(idx, self.width() - idx);
(0..col_pairs).all(|offset| self.col(idx - offset - 1) == self.col(idx + offset))
}
fn find_smudged_horizontal_reflection(&self) -> Option<usize> {
(1..self.height()).find(|idx| self.is_smudged_horizontal_reflection(*idx))
}
fn is_smudged_horizontal_reflection(&self, idx: usize) -> bool {
// Same algorithm for problem 2, but count errors breaking reflection.
// If the count == 1 after all checks, then it is our smudge
let row_pairs = std::cmp::min(idx, self.height() - idx);
(0..row_pairs)
.map(|offset| {
self.mirrors[idx - offset - 1]
.iter()
.zip(self.mirrors[idx + offset].iter())
.filter(|(a, b)| **a != **b)
.count()
})
.sum::<usize>()
== 1
}
fn find_smudged_vertical_reflection(&self) -> Option<usize> {
(1..self.width()).find(|idx| self.is_smudged_vertical_reflection(*idx))
}
fn is_smudged_vertical_reflection(&self, idx: usize) -> bool {
let col_pairs = std::cmp::min(idx, self.width() - idx);
(0..col_pairs)
.map(|offset| {
self.col(idx - offset - 1)
.iter()
.zip(self.col(idx + offset).iter())
.filter(|(a, b)| **a != **b)
.count()
})
.sum::<usize>()
== 1
}
fn reflection_cost(&self) -> u64 {
if let Some(refl) = self.find_horizontal_reflection() {
100 * refl as u64
} else if let Some(refl) = self.find_vertical_reflection() {
refl as u64
} else {
panic!("no reflection");
}
}
fn smudged_reflection_cost(&self) -> u64 {
if let Some(refl) = self.find_smudged_horizontal_reflection() {
100 * refl as u64
} else if let Some(refl) = self.find_smudged_vertical_reflection() {
refl as u64
} else {
panic!("no reflection");
}
}
}
#[derive(Debug)]
struct Patterns {
patterns: Vec<Pattern>,
}
impl<T: BufRead> From<Lines<T>> for Patterns {
fn from(mut lines: Lines<T>) -> Self {
let mut patterns = Vec::new();
let mut cur_lines = Vec::new();
while let Some(Ok(line)) = lines.next() {
if line.len() == 0 {
patterns.push(Pattern { mirrors: cur_lines });
cur_lines = Vec::new();
} else {
cur_lines.push(line.chars().collect());
}
}
patterns.push(Pattern { mirrors: cur_lines });
Self { patterns }
}
}
// PROBLEM 1 solution
fn problem1<T: BufRead>(input: Lines<T>) -> u64 {
let patterns = Patterns::from(input);
patterns
.patterns
.iter()
.map(|pat| pat.reflection_cost())
.sum()
}
// PROBLEM 2 solution
fn problem2<T: BufRead>(input: Lines<T>) -> u64 {
let patterns = Patterns::from(input);
patterns
.patterns
.iter()
.map(|pat| pat.smudged_reflection_cost())
.sum()
}
#[cfg(test)]
mod tests {
use crate::*;
use std::io::Cursor;
const EXAMPLE: &str = &"#.##..##.
..#.##.#.
##......#
##......#
..#.##.#.
..##..##.
#.#.##.#.
#...##..#
#....#..#
..##..###
#####.##.
#####.##.
..##..###
#....#..#";
#[test]
fn problem1_find_horizontal() {
let c = Cursor::new(EXAMPLE);
let patterns = Patterns::from(c.lines());
assert_eq!(patterns.patterns[1].find_horizontal_reflection(), Some(4));
}
#[test]
fn problem1_find_vertical() {
let c = Cursor::new(EXAMPLE);
let patterns = Patterns::from(c.lines());
assert_eq!(patterns.patterns[0].find_vertical_reflection(), Some(5));
}
#[test]
fn problem1_example() {
let c = Cursor::new(EXAMPLE);
assert_eq!(problem1(c.lines()), 405);
}
#[test]
fn problem2_find_horizontal() {
let c = Cursor::new(EXAMPLE);
let patterns = Patterns::from(c.lines());
assert_eq!(
patterns.patterns[0].find_smudged_horizontal_reflection(),
Some(3)
);
assert_eq!(
patterns.patterns[1].find_smudged_horizontal_reflection(),
Some(1)
);
}
#[test]
fn problem2_example() {
let c = Cursor::new(EXAMPLE);
assert_eq!(problem2(c.lines()), 400);
}
}