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day 17 rust nicer solution
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- uses const generics
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@OrangeBacon
OrangeBacon committed Dec 17, 2020
1 parent 1deec4d commit 4b1a0c7
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205 changes: 79 additions & 126 deletions src/days/day17.rs
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Original file line number Diff line number Diff line change
@@ -1,33 +1,85 @@
use anyhow::Result;
use hashbrown::HashMap;
use itertools::Itertools;
use libaoc::{aoc, AocResult, Timer};
use std::collections::BTreeMap;
use std::convert::TryInto;

type Coords<const SIZE: usize> = [i32; SIZE];

fn get_neighbors<const SIZE: usize>(
location: Coords<SIZE>,
data: &HashMap<Coords<SIZE>, bool>,
) -> i32 {
let offsets = [[-1i32, 0, 1]; SIZE];

fn get_neighbors_3(coords: (i32, i32, i32), data: &BTreeMap<(i32, i32, i32), bool>) -> i32 {
let mut count = 0;
for x in (coords.0 - 1)..=(coords.0 + 1) {
for y in (coords.1 - 1)..=(coords.1 + 1) {
for z in (coords.2 - 1)..=(coords.2 + 1) {
if ((x, y, z) != coords) && *data.get(&(x, y, z)).unwrap_or(&false) {
count += 1;
}
}
for current in offsets.iter().multi_cartesian_product() {
let coords: Vec<_> = current.iter().map(|x| **x).collect();
let coords: Coords<SIZE> = coords.try_into().unwrap();

let coords: Vec<_> = coords.iter().zip(&location).map(|(a, b)| a + b).collect();
let coords: Coords<SIZE> = coords.try_into().unwrap();

if location != coords && *data.get(&coords).unwrap_or(&false) {
count += 1;
}
}

count
}

fn get_neighbors_4(coords: (i32, i32, i32, i32), data: &BTreeMap<(i32, i32, i32, i32), bool>) -> i32 {
let mut count = 0;
for x in (coords.0 - 1)..=(coords.0 + 1) {
for y in (coords.1 - 1)..=(coords.1 + 1) {
for z in (coords.2 - 1)..=(coords.2 + 1) {
for w in (coords.3 - 1)..=(coords.3 + 1) {
if ((x, y, z, w) != coords) && *data.get(&(x, y, z, w)).unwrap_or(&false) {
count += 1;
}
fn game<const SIZE: usize>(mut data: HashMap<[i32; SIZE], bool>, width: i32, height: i32) -> u32 {
let mut min_pos = [0; SIZE];
let mut size = [1; SIZE];
size[0] = width;
size[1] = height;

let mut new = HashMap::new();
for _ in 0..6 {
for i in min_pos.iter_mut() {
*i -= 1;
}

for i in size.iter_mut() {
*i += 1;
}

let iterators: Vec<Vec<_>> = min_pos
.iter()
.zip(&size)
.map(|(&a, &b)| (a..b).into_iter().collect())
.collect();
for coords in iterators.iter().multi_cartesian_product() {
let coords: Vec<_> = coords.iter().map(|x| **x).collect();
let coords: Coords<SIZE> = coords.try_into().unwrap();

let current_state = *data.get(&coords).unwrap_or(&false);
let neighbors = get_neighbors(coords, &data);
let new_state = if current_state {
if neighbors == 2 || neighbors == 3 {
true
} else {
false
}
} else {
if neighbors == 3 {
true
} else {
false
}
}
};

new.insert(coords, new_state);
}

(data, new) = (new, data);
new.clear();
}

let mut count = 0;
for &value in data.values() {
if value {
count += 1;
}
}

Expand All @@ -51,122 +103,23 @@ pub fn solve(timer: &mut Timer, input: &str) -> Result<AocResult> {
.collect();
timer.lap("Parse");

let mut data_3 = BTreeMap::new();
let mut data_4 = BTreeMap::new();
let mut data_3 = HashMap::new();
let mut data_4 = HashMap::new();
for (y, row) in input.iter().enumerate() {
for (x, &item) in row.iter().enumerate() {
data_3.insert((x as i32, y as i32, 0), item);
data_4.insert((x as i32, y as i32, 0, 0), item);
data_3.insert([x as i32, y as i32, 0], item);
data_4.insert([x as i32, y as i32, 0, 0], item);
}
}
timer.lap("Construct maps");

let mut min_pos = (0, 0, 0);
let mut size = (input[0].len() as i32, input.len() as i32, 1);

for _ in 0..6 {
let mut new = BTreeMap::new();

min_pos.0 -= 1;
min_pos.1 -= 1;
min_pos.2 -= 1;

size.0 += 1;
size.1 += 1;
size.2 += 1;

for x in min_pos.0..size.0 {
for y in min_pos.1..size.1 {
for z in min_pos.2..size.2 {
let coords = (x, y, z);
let current_state = *data_3.get(&coords).unwrap_or(&false);
let neighbors = get_neighbors_3(coords, &data_3);
let new_state = if current_state {
if neighbors == 2 || neighbors == 3 {
true
} else {
false
}
} else {
if neighbors == 3 {
true
} else {
false
}
};

new.insert(coords, new_state);
}
}
}

data_3 = new;
}

let mut count = 0;
for &value in data_3.values() {
if value {
count += 1;
}
}
let part1 = count;
let width = input[0].len() as i32;
let height = input.len() as i32;

let part1 = game(data_3, width, height);
timer.lap("Part 1");


let mut min_pos = (0, 0, 0, 0);
let mut size = (input[0].len() as i32, input.len() as i32, 1, 1);

for _ in 0..6 {
let mut new = BTreeMap::new();

min_pos.0 -= 1;
min_pos.1 -= 1;
min_pos.2 -= 1;
min_pos.3 -= 1;

size.0 += 1;
size.1 += 1;
size.2 += 1;
size.3 += 1;

for x in min_pos.0..size.0 {
for y in min_pos.1..size.1 {
for z in min_pos.2..size.2 {
for w in min_pos.3..size.3 {
let coords = (x, y, z, w);
let current_state = *data_4.get(&coords).unwrap_or(&false);
let neighbors = get_neighbors_4(coords, &data_4);
let new_state = if current_state {
if neighbors == 2 || neighbors == 3 {
true
} else {
false
}
} else {
if neighbors == 3 {
true
} else {
false
}
};

new.insert(coords, new_state);
}
}
}
}

data_4 = new;
}

let mut count = 0;
for &value in data_4.values() {
if value {
count += 1;
}
}
let part2 = count;
let part2 = game(data_4, width, height);
timer.lap("Part 2");

Ok(AocResult::new(part1, part2))
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1 change: 0 additions & 1 deletion src/main.rs
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Original file line number Diff line number Diff line change
Expand Up @@ -2,7 +2,6 @@
#![feature(str_split_once)]
#![feature(min_const_generics)]
#![feature(destructuring_assignment)]
#![feature(const_in_array_repeat_expressions)]

use anyhow::{anyhow, Result};
use clap::{App, Arg, ArgMatches};
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