commit cd0edfa9ad608e653c4a1cf7cdb7b42663919ed8 · aylac.top/advent_of_code

+30 -25
2015/18/rust/src/main.rs
···

       1
       1
       -
       use std::{iter::once, mem::swap};

     

       1
       1
       +
       use std::mem::swap;

     

       2
       2
        
       

     

       3
       3
        
       fn generations(times: u32, mut world: Vec<u8>, size: usize, stuck: bool) -> Vec<u8> {

     

       4
       4
       +
           #[inline]

     

       5
       5
       +
           fn pos(x: usize, y: usize, size: usize) -> usize {

     

       6
       6
       +
               (1 + y) * (size + 2) + (1 + x)

     

       7
       7
       +
           }

     

       8
       8
       +
       

     

       4
       9
        
           #[inline]

     

       5
       10
        
           fn get_at(world: &Vec<u8>, size: usize, x: usize, y: usize) -> u8 {

     

       6
       6
       -
               // benefits from the integer overflow to simplify code

     

       7
       7
       -
               if x >= size || y >= size {

     

       8
       8
       -
                   return 0;

     

       9
       9
       -
               };

     

       10
       11
        
               // this is in known bounds

     

       11
       11
       -
               unsafe { *world.get_unchecked(y * size + x) }

     

       12
       12
       +
               unsafe { *world.get_unchecked(pos(x, y, size)) }

     

       12
       13
        
           }

     

       13
       14
        
       

     

       14
       14
       -
           let mut new_world = vec![0_u8; size * size];

     

       15
       15
        
           let sizem = size - 1;

     

       16
       16
       +
       

     

       17
       17
       +
           let mut new_world = vec![0_u8; (size + 2).pow(2)];

     

       18
       18
       +
       

     

       16
       19
        
           if stuck {

     

       17
       17
       -
               world[0] = 1;

     

       18
       18
       -
               world[sizem] = 1;

     

       19
       19
       -
               world[(size * size) - 1] = 1;

     

       20
       20
       -
               world[size * sizem] = 1;

     

       20
       20
       +
               world[pos(0, 0, size)] = 1;

     

       21
       21
       +
               world[pos(sizem, 0, size)] = 1;

     

       22
       22
       +
               world[pos(0, sizem, size)] = 1;

     

       23
       23
       +
               world[pos(sizem, sizem, size)] = 1;

     

       21
       24
        
           }

     

       22
       25
        
       

     

       23
       26
        
           for _ in 0..times {

     

       24
       24
       -
               for yo in 1..=size {

     

       27
       27
       +
               for yo in 0..size {

     

       25
       28
        
                   let ym = yo - 1;

     

       26
       29
        
                   let yp = yo + 1;

     

       27
       27
       -
                   for xo in 1..=size {

     

       30
       30
       +
                   for xo in 0..size {

     

       28
       31
        
                       let xm = xo - 1;

     

       29
       32
        
                       let xp = xo + 1;

     

       30
       33
        
       

     
···

       37
       40
        
                           + get_at(&world, size, xm, yp)

     

       38
       41
        
                           + get_at(&world, size, xo, yp)

     

       39
       42
        
                           + get_at(&world, size, xp, yp);

     

       40
       40
       -
                       new_world[yo * size + xo] = (neighbours == 3 || (neighbours == 2 && was)) as u8;

     

       43
       43
       +
                       new_world[pos(xo, yo, size)] = (neighbours == 3 || (neighbours == 2 && was)) as u8;

     

       41
       44
        
                   }

     

       42
       45
        
               }

     

       43
       46
        
       

     
···

       45
       48
        
       

     

       46
       49
        
               // i hate the duplication here :(

     

       47
       50
        
               if stuck {

     

       48
       48
       -
                   world[0] = 1;

     

       49
       49
       -
                   world[sizem] = 1;

     

       50
       50
       -
                   world[(size * size) - 1] = 1;

     

       51
       51
       -
                   world[size * sizem] = 1;

     

       51
       51
       +
                   world[pos(0, 0, size)] = 1;

     

       52
       52
       +
                   world[pos(sizem, 0, size)] = 1;

     

       53
       53
       +
                   world[pos(0, sizem, size)] = 1;

     

       54
       54
       +
                   world[pos(sizem, sizem, size)] = 1;

     

       52
       55
        
               }

     

       53
       56
        
           }

     

       54
       57
        
           world

     
···

       57
       60
        
       fn main() {

     

       58
       61
        
           let input = include_str!("../../input.txt").trim();

     

       59
       62
        
           let size = input.split_once("\n").expect("invalid input").0.len();

     

       60
       60
       -
           let input: Vec<u8> = once(".".repeat(size))

     

       61
       61
       -
               .chain(input.split("\n"))

     

       62
       62
       -
               .chain(".".repeat(size))

     

       63
       63
       -
               .map(|line| {

     

       64
       64
       -
                   once(0)

     

       65
       65
       -
                       .chain(line.chars().map(|v| (v == '#') as u8))

     

       66
       66
       -
                       .chain(once(0))

     

       63
       63
       +
           // reads the input but adds a line of buffer on the sides

     

       64
       64
       +
           let buffer_line = ".".repeat(size);

     

       65
       65
       +
           let input: Vec<u8> = format!("{buffer_line}\n{input}\n{buffer_line}")

     

       66
       66
       +
               .split("\n")

     

       67
       67
       +
               .map(|line| -> Vec<u8> {

     

       68
       68
       +
                   format!(".{}.", line)

     

       69
       69
       +
                       .chars()

     

       70
       70
       +
                       .map(|v| (v == '#') as u8)

     

       71
       71
       +
                       .collect()

     

       67
       72
        
               })

     

       68
       73
        
               .flatten()

     

       69
       74
        
               .collect();