fun/advent-of-code-2020-rust
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[TASK] Added some padding to the grid to save some time on out-of-bounds checks, but it's still pretty slow

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Bas Dado
2020-12-11 22:31:05 +01:00
parent 0a110d6bfd
commit 4a8c5580ff
1 changed files with 16 additions and 21 deletions
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37
src/day11.rs
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@@ -6,7 +6,7 @@ use crate::day11::GridState::EmptySeat;
pub fn solve() { pub fn solve() {
let lines = util::read_file("input/day11.txt"); let lines = util::read_file("input/day11.txt");
let seats = Seats::parse(&lines); let seats = Seats::parse(&lines, 1);
let part1 = solve_part1(&seats); let part1 = solve_part1(&seats);
@@ -25,8 +25,8 @@ fn solve_part1(seats: &Seats) -> usize {
loop { loop {
let mut changes = false; let mut changes = false;
for y in 0..seats.height { for y in 1..seats.height-1 {
for x in 0..seats.width { for x in 1..seats.width-1 {
let seat = last_seats.get(&x, &y); let seat = last_seats.get(&x, &y);
if seat != &Floor { if seat != &Floor {
let occupied = last_seats.count_occupied_neighbors(&x, &y); let occupied = last_seats.count_occupied_neighbors(&x, &y);
@@ -66,8 +66,8 @@ fn solve_part2(seats: &Seats, visible_chairs: &Vec<Option<Vec<(usize, usize)>>>)
changes = true; changes = true;
next_seats.set(&x, &y, FilledSeat); next_seats.set(&x, &y, FilledSeat);
} else if seat == &FilledSeat && occupied >= 5 { } else if seat == &FilledSeat && occupied >= 5 {
next_seats.set(&x, &y, EmptySeat);
changes = true; changes = true;
next_seats.set(&x, &y, EmptySeat);
} }
} }
} }
@@ -94,16 +94,16 @@ impl Seats {
const DIRECTIONS: [(i32, i32); 8] = [(-1, 1), (-1, 0), (-1, -1), (0, -1), (0, 1), (1, 1), (1, 0), (1, -1)]; const DIRECTIONS: [(i32, i32); 8] = [(-1, 1), (-1, 0), (-1, -1), (0, -1), (0, 1), (1, 1), (1, 0), (1, -1)];
fn parse(lines: &Vec<String>) -> Seats { fn parse(lines: &Vec<String>, padding: usize) -> Seats {
let height = lines.len(); let height = lines.len() + padding * 2;
let width = lines[0].len(); let width = lines[0].len() + padding * 2;
let mut grid = vec!(GridState::Floor; width * height); let mut grid = vec!(GridState::Floor; width * height);
for y in 0..lines.len() { for y in 0..lines.len() {
let line = &lines[y]; let line = &lines[y];
let mut line_chars = line.chars(); let mut line_chars = line.chars();
for x in 0..lines[0].len() { for x in 0..lines[0].len() {
grid[x + y * width] = GridState::parse(&line_chars.next().unwrap()) grid[(x + padding) + (y + padding) * width] = GridState::parse(&line_chars.next().unwrap())
} }
} }
@@ -170,20 +170,15 @@ impl Seats {
fn count_occupied_neighbors(&self, x: &usize, y: &usize) -> u8 { fn count_occupied_neighbors(&self, x: &usize, y: &usize) -> u8 {
let x_upper = x == &(self.width - &ONE);
let x_lower = x == &0;
let y_upper = y == &(self.height - &ONE);
let y_lower = y == &0;
return return
if !x_lower && !y_lower && self.is_occupied(&(x - &ONE), &(y - &ONE)) { 1 } else { 0 } + if self.is_occupied(&(x - &ONE), &(y - &ONE)) { 1 } else { 0 } +
if !x_lower && self.is_occupied(&(x - &ONE), &y) { 1 } else { 0 } + if self.is_occupied(&(x - &ONE), &y) { 1 } else { 0 } +
if !x_lower && !y_upper && self.is_occupied(&(x - &ONE), &(y + ONE)) { 1 } else { 0 } + if self.is_occupied(&(x - &ONE), &(y + ONE)) { 1 } else { 0 } +
if !y_lower && self.is_occupied(&x, &(y - ONE)) { 1 } else { 0 } + if self.is_occupied(&x, &(y - ONE)) { 1 } else { 0 } +
if !y_upper && self.is_occupied(&x, &(y + ONE)) { 1 } else { 0 } + if self.is_occupied(&x, &(y + ONE)) { 1 } else { 0 } +
if !x_upper && !y_lower && self.is_occupied(&(x + ONE), &(y - ONE)) { 1 } else { 0 } + if self.is_occupied(&(x + ONE), &(y - ONE)) { 1 } else { 0 } +
if !x_upper && self.is_occupied(&(x + ONE), &y) { 1 } else { 0 } + if self.is_occupied(&(x + ONE), &y) { 1 } else { 0 } +
if !x_upper && !y_upper && self.is_occupied(&(x + ONE), &(y + ONE)) { 1 } else { 0 } if self.is_occupied(&(x + ONE), &(y + ONE)) { 1 } else { 0 }
} }