day10: Cleanup

This commit is contained in:
Ishan Jain 2023-12-10 20:02:04 +05:30
parent f8e42fd4b9
commit a59be70c63
Signed by: ishan
GPG Key ID: 0506DB2A1CC75C27
3 changed files with 298 additions and 501 deletions

View File

@ -1,15 +1,95 @@
#![feature(test)]
use std::collections::VecDeque;
extern crate test;
const INPUTS: [&str; 2] = [include_str!("./sample.txt"), include_str!("./input.txt")];
const INPUTS: [&str; 4] = [
".....
.S-7.
.|.|.
.L-J.
.....",
"..F7.
.FJ|.
SJ.L7
|F--J
LJ...",
include_str!("./sample.txt"),
include_str!("./input.txt"),
];
#[derive(Debug)]
enum Direction {
Unknown,
North,
South,
East,
West,
}
#[derive(Debug, Eq, PartialEq, Copy, Clone)]
enum Tile {
Vertical = 0x1,
Horizontal = 0x2,
L = 0x4,
J = 0x8,
Seven = 0x10,
F = 0x20,
Ground = 0x40,
Start = 0x80,
}
impl From<char> for Tile {
fn from(value: char) -> Self {
use Tile::*;
match value {
'|' => Vertical,
'-' => Horizontal,
'L' => L,
'J' => J,
'7' => Seven,
'F' => F,
'.' => Ground,
'S' => Start,
_ => unreachable!(),
}
}
}
fn next_direction(a: char, dir: &Direction) -> (Direction, u8) {
use Direction::*;
use Tile::*;
match (a, dir) {
('|', Unknown | North) => (North, Vertical as u8 | Seven as u8 | F as u8),
('|', South) => (South, Vertical as u8 | L as u8 | J as u8),
('-', Unknown | West) => (West, Horizontal as u8 | L as u8 | F as u8),
('-', East) => (East, Horizontal as u8 | J as u8 | Seven as u8),
('L', Unknown | West) => (North, Vertical as u8 | Seven as u8 | F as u8),
('L', South) => (East, Horizontal as u8 | J as u8 | Seven as u8),
('J', Unknown | South) => (West, Horizontal as u8 | L as u8 | F as u8),
('J', East) => (North, Vertical as u8 | F as u8 | Seven as u8),
('7', Unknown | East) => (South, Vertical as u8 | L as u8 | J as u8),
('7', North) => (West, Horizontal as u8 | L as u8 | F as u8),
('F', Unknown | North) => (East, Horizontal as u8 | Seven as u8 | J as u8),
('F', West) => (South, Vertical as u8 | L as u8 | J as u8),
v => {
println!("{:?}", v);
unreachable!()
}
}
}
fn process(data: &str) -> usize {
let mut answer = std::usize::MAX;
let grid: Vec<Vec<char>> = data
let mut grid: Vec<Vec<char>> = data
.lines()
.filter(|x| !x.is_empty())
.map(|x| x.chars().collect())
@ -28,336 +108,65 @@ fn process(data: &str) -> usize {
}
}
}
'outer: for c in ['-', '|', 'L', 'J', '7', 'F'] {
let mut start = true;
for mut c in ['F', 'L', '|', '-', 'J', '7'] {
let mut sx = s_x;
let mut sy = s_y;
let (mut px, mut py) = (s_x, s_y);
let mut length = 0;
grid[sx][sy] = c;
while c != 'S' {
println!(
"({}, {}) => ({}, {}) c = {} {}",
px, py, sx, sy, c, grid[sx][sy]
);
let mut direction = Direction::Unknown;
match c {
'|' => {
if sx > 0 && !(sx - 1 == px && sy == py) {
px = sx;
py = sy;
sx = sx - 1;
length += 1;
c = grid[sx][sy];
} else if sx < m - 1 && !(sx + 1 == px && sy == py) {
px = sx;
py = sy;
sx = sx + 1;
length += 1;
c = grid[sx][sy];
}
}
'F' => {
if sy < n - 1 && !(sx == px && sy + 1 == py) {
px = sx;
py = sy;
sy = sy + 1;
length += 1;
c = grid[sx][sy];
} else if sx < m - 1 && !(sx + 1 == px && px == py) {
px = sx;
py = sy;
sx = sx + 1;
length += 1;
c = grid[sx][sy];
}
}
loop {
if !start && (sx == s_x && sy == s_y) {
break;
}
start = false;
'-' => {
if sy > 0 && !(sx == px && sy - 1 == py) {
px = sx;
py = sy;
sy = sy - 1;
length += 1;
c = grid[sx][sy];
} else if sy < n - 1 && !(sx == px && sy + 1 == py) {
px = sx;
py = sy;
sy = sy + 1;
length += 1;
c = grid[sx][sy];
}
}
if length >= answer {
continue 'outer;
}
'7' => {
if sy > 0 && !(sx == px && sy - 1 == py) {
px = sx;
py = sy;
sy = sy - 1;
length += 1;
c = grid[sx][sy];
} else if sx < m - 1 && !(sx + 1 == px && sy == py) {
px = sx;
py = sy;
sx = sx + 1;
length += 1;
c = grid[sx][sy];
}
}
// what we need to figure out the next step
// 1. The current character
// 2. Direction we are headed in
// 3. the potential next character. since it's possible we jump to an un jumpable
// character
'J' => {
if sy > 0 && !(sx == px && sy - 1 == py) {
px = sx;
py = sy;
sy = sy - 1;
length += 1;
c = grid[sx][sy];
} else if sx > 0 && !(sx - 1 == px && sy == py) {
px = sx;
py = sy;
sx = sx - 1;
length += 1;
c = grid[sx][sy];
}
}
let (new_direction, valid_pipes) = next_direction(grid[sx][sy], &direction);
'L' => {
if sx > 0 && !(sx - 1 == px && sy == py) {
px = sx;
py = sy;
sx = sx - 1;
length += 1;
c = grid[sx][sy];
} else if sy < n - 1 && !(sx == px && sy + 1 == py) {
px = sx;
py = sy;
sy = sy + 1;
length += 1;
c = grid[sx][sy];
}
}
'.' => break,
let (x, y) = match new_direction {
Direction::Unknown => unreachable!(),
Direction::North => (-1, 0),
Direction::South => (1, 0),
Direction::East => (0, 1),
Direction::West => (0, -1),
};
_ => unreachable!(),
let p = sx as i32 + x;
let q = sy as i32 + y;
if p < 0 || q < 0 || p >= m as i32 || q >= n as i32 {
continue 'outer;
}
let next_pipe = Tile::from(grid[p as usize][q as usize]);
if valid_pipes & next_pipe as u8 > 0 {
sx = p as usize;
sy = q as usize;
direction = new_direction;
length += 1;
} else {
continue 'outer;
}
}
answer = std::cmp::min(answer, length / 2);
}
return answer;
// let mut stack = vec![];
// // let mut q = VecDeque::new();
// stack.push((sx, sy, 'F', sx, sy, 0));
// stack.push((sx, sy, 'L', sx, sy, 0));
let mut min_dist = vec![vec![std::usize::MAX; n]; m];
// while let Some((sx, sy, c, px, py, distance)) = stack.pop() {
// min_dist[sx][sy] = std::cmp::min(min_dist[sx][sy], distance);
// match c {
// '|' => {
// if sx > 0 && !(sx - 1 == px && sy == py) {
// let c = grid[sx - 1][sy];
// stack.push((sx - 1, sy, c, sx, sy, distance + 1));
// }
// if sx < m - 1 && !(sx + 1 == px && sy == py) {
// let c = grid[sx + 1][sy];
// stack.push((sx + 1, sy, c, sx, sy, distance + 1));
// }
// }
//
// '-' => {
// if sy > 0 && !(sx == px && sy - 1 == py) {
// let c = grid[sx][sy - 1];
// stack.push((sx, sy - 1, c, sx, sy, distance + 1));
// }
// if sy < n - 1 && !(sx == px && sy + 1 == py) {
// let c = grid[sx][sy + 1];
// stack.push((sx, sy + 1, c, sx, sy, distance + 1));
// }
// }
//
// 'L' => {
// if sx > 0 && !(sx - 1 == px && sy == py) {
// let c = grid[sx - 1][sy];
// stack.push((sx - 1, sy, c, sx, sy, distance + 1));
// }
// if sy < n - 1 && !(sx == px && sy + 1 == py) {
// let c = grid[sx][sy + 1];
// stack.push((sx, sy + 1, c, sx, sy, distance + 1));
// }
// }
//
// 'J' => {
// if sy > 0 && !(sx == px && sy - 1 == py) {
// let c = grid[sx][sy - 1];
// stack.push((sx, sy - 1, c, sx, sy, distance + 1));
// }
// if sx > 0 && !(sx - 1 == px && sy == py) {
// let c = grid[sx - 1][sy];
// stack.push((sx - 1, sy, c, sx, sy, distance + 1));
// }
// }
//
// '7' => {
// if sy > 0 && !(sx == px && sy - 1 == py) {
// let c = grid[sx][sy - 1];
// stack.push((sx, sy - 1, c, sx, sy, distance + 1));
// }
// if sx < m - 1 && !(sx + 1 == px && sy == py) {
// let c = grid[sx + 1][sy];
// stack.push((sx + 1, sy, c, sx, sy, distance + 1));
// }
// }
//
// 'F' => {
// if sy < n - 1 && !(sx == px && sy + 1 == py) {
// let c = grid[sx][sy + 1];
// stack.push((sx, sy + 1, c, sx, sy, distance + 1));
// }
// if sx < m - 1 && !(sx + 1 == px && px == py) {
// let c = grid[sx + 1][sy];
// stack.push((sx + 1, sy, c, sx, sy, distance + 1));
// }
// }
//
// '.' => (),
//
// 'S' => (),
//
// v => {
// unreachable!()
// }
// }
// }
//
println!();
for line in min_dist {
println!("{:?}", line);
for c in line {
if c == std::usize::MAX {
continue;
}
answer = std::cmp::max(answer, c);
}
}
println!();
// for &(sx, sy, c) in [(sx, sy, 'F')].iter() {
// let mut visited = vec![vec![false; n]; m];
//
// // dfs(&grid, &mut visited, &mut path, sx, sy, c, 0);
// }
answer
}
fn dfs(
grid: &Vec<Vec<char>>,
visited: &mut Vec<Vec<bool>>,
path: &mut Vec<char>,
sx: usize,
sy: usize,
c: char,
distance: usize,
) {
if visited[sx][sy] {
// return;
} else {
visited[sx][sy] = true;
}
if c == 'S' {
return;
}
path.push(c);
println!("({},{}) = {} {}", sx, sy, c, distance);
let m = grid.len();
let n = grid[0].len();
match c {
'|' => {
if sx > 0 {
let c = grid[sx - 1][sy];
dfs(grid, visited, path, sx - 1, sy, c, distance + 1);
}
if sx < m - 1 {
let c = grid[sx + 1][sy];
dfs(grid, visited, path, sx + 1, sy, c, distance + 1);
}
}
'-' => {
if sy > 0 {
let c = grid[sx][sy - 1];
dfs(grid, visited, path, sx, sy - 1, c, distance + 1);
}
if sy < n - 1 {
let c = grid[sx][sy + 1];
dfs(grid, visited, path, sx, sy + 1, c, distance + 1);
}
}
'L' => {
if sx > 0 {
let c = grid[sx - 1][sy];
dfs(grid, visited, path, sx - 1, sy, c, distance + 1);
}
if sy < n - 1 {
let c = grid[sx][sy + 1];
dfs(grid, visited, path, sx, sy + 1, c, distance + 1);
}
}
'J' => {
if sy > 0 {
let c = grid[sx][sy - 1];
dfs(grid, visited, path, sx, sy - 1, c, distance + 1);
}
if sx > 0 {
let c = grid[sx - 1][sy];
dfs(grid, visited, path, sx - 1, sy, c, distance + 1);
}
}
'7' => {
if sy > 0 {
let c = grid[sx][sy - 1];
dfs(grid, visited, path, sx, sy - 1, c, distance + 1);
}
if sx < m - 1 {
let c = grid[sx + 1][sy];
dfs(grid, visited, path, sx + 1, sy, c, distance + 1);
}
}
'F' => {
if sy < n - 1 {
let c = grid[sx][sy + 1];
dfs(grid, visited, path, sx, sy + 1, c, distance + 1);
}
if sx < m - 1 {
let c = grid[sx + 1][sy];
dfs(grid, visited, path, sx + 1, sy, c, distance + 1);
}
}
'.' => (),
_ => unreachable!(),
}
path.pop();
}
fn main() {
for input in INPUTS.iter() {
println!("total = {}", process(input));
@ -367,7 +176,7 @@ fn main() {
#[bench]
fn part1(b: &mut test::Bencher) {
b.iter(|| {
let v = process(INPUTS[1]);
let v = process(INPUTS[INPUTS.len() - 1]);
test::black_box(v);
});
}

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@ -2,7 +2,116 @@
extern crate test;
const INPUTS: [&str; 2] = [include_str!("./sample.txt"), include_str!("./input.txt")];
const INPUTS: [&str; 5] = [
"...........
.S-------7.
.|F-----7|.
.||.....||.
.||.....||.
.|L-7.F-J|.
.|..|.|..|.
.L--J.L--J.
...........",
"..........
.S------7.
.|F----7|.
.||OOOO||.
.||OOOO||.
.|L-7F-J|.
.|II||II|.
.L--JL--J.
..........",
"FF7FSF7F7F7F7F7F---7
L|LJ||||||||||||F--J
FL-7LJLJ||||||LJL-77
F--JF--7||LJLJ7F7FJ-
L---JF-JLJ.||-FJLJJ7
|F|F-JF---7F7-L7L|7|
|FFJF7L7F-JF7|JL---7
7-L-JL7||F7|L7F-7F7|
L.L7LFJ|||||FJL7||LJ
L7JLJL-JLJLJL--JLJ.L",
".F----7F7F7F7F-7....
.|F--7||||||||FJ....
.||.FJ||||||||L7....
FJL7L7LJLJ||LJ.L-7..
L--J.L7...LJS7F-7L7.
....F-J..F7FJ|L7L7L7
....L7.F7||L7|.L7L7|
.....|FJLJ|FJ|F7|.LJ
....FJL-7.||.||||...
....L---J.LJ.LJLJ...",
include_str!("./input.txt"),
];
#[derive(Debug)]
enum Direction {
Unknown,
North,
South,
East,
West,
}
#[derive(Debug, Eq, PartialEq, Copy, Clone)]
enum Tile {
Vertical = 0x1,
Horizontal = 0x2,
L = 0x4,
J = 0x8,
Seven = 0x10,
F = 0x20,
Ground = 0x40,
Start = 0x80,
// Reusing a bitmap because these will never be togther in a single map
X = 0x1 | 0x2,
}
impl From<char> for Tile {
fn from(value: char) -> Self {
use Tile::*;
match value {
'|' => Vertical,
'-' => Horizontal,
'L' => L,
'J' => J,
'7' => Seven,
'F' => F,
'.' => Ground,
'S' => Start,
_ => unreachable!(),
}
}
}
fn next_direction(a: char, dir: &Direction) -> (Direction, u8) {
use Direction::*;
use Tile::*;
match (a, dir) {
('|', Unknown | North) => (North, Vertical as u8 | Seven as u8 | F as u8),
('|', South) => (South, Vertical as u8 | L as u8 | J as u8),
('-', Unknown | West) => (West, Horizontal as u8 | L as u8 | F as u8),
('-', East) => (East, Horizontal as u8 | J as u8 | Seven as u8),
('L', Unknown | West) => (North, Vertical as u8 | Seven as u8 | F as u8),
('L', South) => (East, Horizontal as u8 | J as u8 | Seven as u8),
('J', Unknown | South) => (West, Horizontal as u8 | L as u8 | F as u8),
('J', East) => (North, Vertical as u8 | F as u8 | Seven as u8),
('7', Unknown | East) => (South, Vertical as u8 | L as u8 | J as u8),
('7', North) => (West, Horizontal as u8 | L as u8 | F as u8),
('F', Unknown | North) => (East, Horizontal as u8 | Seven as u8 | J as u8),
('F', West) => (South, Vertical as u8 | L as u8 | J as u8),
_ => unreachable!(),
}
}
fn process(data: &str) -> usize {
let mut answer = 0;
@ -26,186 +135,60 @@ fn process(data: &str) -> usize {
}
}
let mut map = vec![vec!['.'; n]; m];
let mut map = vec![vec![Tile::Ground; n]; m];
'outer: for mut c in ['|', '-', 'L', 'J', '7', 'F'] {
'outer: for c in ['-', '|', 'L', 'J', '7', 'F'] {
let mut start = true;
grid[s_x][s_y] = c;
let mut sx = s_x;
let mut sy = s_y;
let (mut px, mut py) = (s_x, s_y);
let mut start = true;
grid[sx][sy] = c;
let mut direction = Direction::Unknown;
let mut local_map = map.clone();
let mut tmp_map = map.clone();
while start || !(sx == s_x && sy == s_y) {
loop {
if !start && (sx == s_x && sy == s_y) {
break;
}
start = false;
tmp_map[sx][sy] = c;
local_map[sx][sy] = Tile::from(grid[sx][sy]);
// what we need to figure out the next step
// 1. The current character
// 2. Direction we are headed in
// 3. the potential next character. since it's possible we jump to an un jumpable
// character
match c {
'|' => {
if sx > 0
&& !(sx - 1 == px && sy == py)
&& ['7', 'F', '|', 'S'].contains(&grid[sx - 1][sy])
{
px = sx;
py = sy;
sx -= 1;
c = grid[sx][sy];
} else if sx < m - 1
&& !(sx + 1 == px && sy == py)
&& ['L', 'J', '|', 'S'].contains(&grid[sx + 1][sy])
{
px = sx;
py = sy;
sx += 1;
c = grid[sx][sy];
} else {
continue 'outer;
}
}
'F' => {
if sy < n - 1
&& !(sx == px && sy + 1 == py)
&& ['-', 'J', '7', 'S'].contains(&grid[sx][sy + 1])
{
px = sx;
py = sy;
sy += 1;
c = grid[sx][sy];
} else if sx < m - 1
&& !(sx + 1 == px && px == py)
&& ['L', 'J', '|', 'S'].contains(&grid[sx + 1][sy])
{
px = sx;
py = sy;
sx += 1;
c = grid[sx][sy];
} else {
continue 'outer;
}
}
let (new_direction, valid_pipes) = next_direction(grid[sx][sy], &direction);
'-' => {
if sy > 0
&& !(sx == px && sy - 1 == py)
&& ['L', 'F', '-', 'S'].contains(&grid[sx][sy - 1])
{
px = sx;
py = sy;
sy -= 1;
c = grid[sx][sy];
} else if sy < n - 1
&& !(sx == px && sy + 1 == py)
&& ['J', '7', '-', 'S'].contains(&grid[sx][sy + 1])
{
px = sx;
py = sy;
sy += 1;
c = grid[sx][sy];
} else {
continue 'outer;
}
}
let (x, y) = match new_direction {
Direction::Unknown => unreachable!(),
Direction::North => (-1, 0),
Direction::South => (1, 0),
Direction::East => (0, 1),
Direction::West => (0, -1),
};
'7' => {
if sy > 0
&& !(sx == px && sy - 1 == py)
&& ['L', 'F', '-', 'S'].contains(&grid[sx][sy - 1])
{
px = sx;
py = sy;
sy -= 1;
c = grid[sx][sy];
} else if sx < m - 1
&& !(sx + 1 == px && sy == py)
&& ['L', 'J', '|', 'S'].contains(&grid[sx + 1][sy])
{
px = sx;
py = sy;
sx += 1;
c = grid[sx][sy];
} else {
continue 'outer;
}
}
let p = sx as i32 + x;
let q = sy as i32 + y;
if p < 0 || q < 0 || p >= m as i32 || q >= n as i32 {
continue 'outer;
}
'J' => {
if sy > 0
&& !(sx == px && sy - 1 == py)
&& ['L', 'F', '-', 'S'].contains(&grid[sx][sy - 1])
{
px = sx;
py = sy;
sy -= 1;
c = grid[sx][sy];
} else if sx > 0
&& !(sx - 1 == px && sy == py)
&& ['7', 'F', '|', 'S'].contains(&grid[sx - 1][sy])
{
px = sx;
py = sy;
sx -= 1;
c = grid[sx][sy];
} else {
continue 'outer;
}
}
'L' => {
if sx > 0
&& !(sx - 1 == px && sy == py)
&& ['7', 'F', '|', 'S'].contains(&grid[sx - 1][sy])
{
px = sx;
py = sy;
sx -= 1;
c = grid[sx][sy];
} else if sy < n - 1
&& !(sx == px && sy + 1 == py)
&& ['J', '7', '-', 'S'].contains(&grid[sx][sy + 1])
{
px = sx;
py = sy;
sy += 1;
c = grid[sx][sy];
} else {
continue 'outer;
}
}
'.' => continue 'outer,
_ => unreachable!(),
let next_pipe = Tile::from(grid[p as usize][q as usize]);
if valid_pipes & next_pipe as u8 > 0 {
sx = p as usize;
sy = q as usize;
direction = new_direction;
} else {
continue 'outer;
}
}
match (
sx as i32 - px as i32,
sy as i32 - py as i32,
grid[px][py],
grid[sx][sy],
) {
(-1, 0, 'J', 'F') => (),
(-1, 0, '|', '|') => {
if sx == 0 || sx == m - 1 {
continue;
}
}
(-1, 0, '|', '7') => (),
(-1, 0, '|', 'F') => (),
(0, -1, 'J', 'L') => (),
_ => unreachable!(),
};
if sx == s_x && sy == s_y {
map = tmp_map;
break;
}
map = local_map;
}
let mut nmap = vec![vec!['.'; n * 2]; m * 2];
let mut nmap = vec![vec![Tile::Ground; n * 2]; m * 2];
for (i, line) in map.iter().enumerate() {
for (j, c) in line.iter().enumerate() {
@ -213,29 +196,34 @@ fn process(data: &str) -> usize {
}
}
use Tile::*;
for line in nmap.iter_mut() {
for j in 0..2 * n - 2 {
if ['F', 'L', '-'].contains(&line[j]) && ['J', '7', '-'].contains(&line[j + 2]) {
line[j + 1] = '-';
if (line[j] as u8 & (F as u8 | L as u8 | Horizontal as u8)) > 0
&& (line[j + 2] as u8 & (J as u8 | Seven as u8 | Horizontal as u8)) > 0
{
line[j + 1] = Horizontal;
}
}
}
for j in 0..n * 2 {
for i in 0..m * 2 - 2 {
if ['F', '7', '|'].contains(&nmap[i][j]) && ['L', 'J', '|'].contains(&nmap[i + 2][j]) {
nmap[i + 1][j] = '|';
if (nmap[i][j] as u8 & (F as u8 | Seven as u8 | Vertical as u8)) > 0
&& (nmap[i + 2][j] as u8 & (L as u8 | J as u8 | Vertical as u8)) > 0
{
nmap[i + 1][j] = Vertical;
}
}
}
for j in 0..2 * n {
if nmap[0][j] == '.' {
flood_fill(&mut nmap, 0, j, 'X');
if nmap[0][j] == Ground {
flood_fill(&mut nmap, 0, j, X);
}
}
let mut out = vec![vec!['.'; n]; m];
let mut out = vec![vec![Tile::Ground; n]; m];
for (i, line) in nmap.iter().enumerate() {
if i % 2 != 0 {
@ -253,7 +241,7 @@ fn process(data: &str) -> usize {
for line in out.into_iter() {
for c in line.into_iter() {
if c == '.' {
if c == Tile::Ground {
answer += 1;
}
}
@ -262,7 +250,7 @@ fn process(data: &str) -> usize {
answer
}
fn flood_fill(map: &mut Vec<Vec<char>>, i: usize, j: usize, fill_with: char) {
fn flood_fill(map: &mut Vec<Vec<Tile>>, i: usize, j: usize, fill_with: Tile) {
let m = map.len();
let n = map[0].len();
const DIRS: [[i32; 2]; 4] = [[0, 1], [0, -1], [-1, 0], [1, 0]];
@ -271,7 +259,7 @@ fn flood_fill(map: &mut Vec<Vec<char>>, i: usize, j: usize, fill_with: char) {
stack.push((i, j));
while let Some((sx, sy)) = stack.pop() {
if map[sx][sy] != '.' {
if map[sx][sy] != Tile::Ground {
continue;
}
@ -302,7 +290,7 @@ fn main() {
#[bench]
fn part1(b: &mut test::Bencher) {
b.iter(|| {
let v = process(INPUTS[1]);
let v = process(INPUTS[INPUTS.len() - 1]);
test::black_box(v);
});
}

View File

@ -1,10 +1,10 @@
.F----7F7F7F7F-7....
.|F--7||||||||FJ....
.||.FJ||||||||L7....
FJL7L7LJLJ||LJ.L-7..
L--J.L7...LJS7F-7L7.
....F-J..F7FJ|L7L7L7
....L7.F7||L7|.L7L7|
.....|FJLJ|FJ|F7|.LJ
....FJL-7.||.||||...
....L---J.LJ.LJLJ...
FF7FSF7F7F7F7F7F---7
L|LJ||||||||||||F--J
FL-7LJLJ||||||LJL-77
F--JF--7||LJLJ7F7FJ-
L---JF-JLJ.||-FJLJJ7
|F|F-JF---7F7-L7L|7|
|FFJF7L7F-JF7|JL---7
7-L-JL7||F7|L7F-7F7|
L.L7LFJ|||||FJL7||LJ
L7JLJL-JLJLJL--JLJ.L