Day 15 part 1

This commit is contained in:
Tyler Beckman 2024-12-17 14:12:35 -07:00
parent f439b99d9d
commit 78f19b2963
Signed by: Ty
GPG key ID: 2813440C772555A4
4 changed files with 165 additions and 6 deletions

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@ -22,3 +22,8 @@ path = "day14/part1.rs"
[[bin]]
name = "d14p2"
path = "day14/part2.rs"
[[bin]]
name = "d15p1"
path = "day15/part1.rs"

153
day15/part1.rs Normal file
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@ -0,0 +1,153 @@
#![feature(const_str_split_at)]
#[derive(Debug, Clone, Copy, PartialEq)]
enum BlockType {
Wall,
Box,
Empty,
Robot
}
#[derive(Debug, Clone, Copy)]
enum InstructionType {
Up,
Down,
Left,
Right
}
const GRID_SIZE: usize = 50;
const INSTRUCTIONS_LENGTH: usize = 1000;
const INSTRUCTIONS_COUNT: usize = 20;
const INPUT: (([[BlockType; GRID_SIZE]; GRID_SIZE], (usize, usize)), [InstructionType; INSTRUCTIONS_COUNT * INSTRUCTIONS_LENGTH]) = {
let split = include_str!("input.txt").split_at(GRID_SIZE * (GRID_SIZE + 1));
let grid_str = split.0.trim_ascii().as_bytes();
let mut grid = [[BlockType::Empty; GRID_SIZE]; GRID_SIZE];
let mut i = 0;
let mut newlines = 0;
let mut robot_pos = (0usize, 0usize);
while i < grid_str.len() {
if grid_str[i] == b'\n' {
newlines += 1;
i += 1;
continue;
};
let row = (i - newlines) / GRID_SIZE;
let col = i - newlines - (row * GRID_SIZE);
grid[row][col] = match grid_str[i] {
b'#' => BlockType::Wall,
b'O' => BlockType::Box,
b'.' => BlockType::Empty,
b'@' => {
robot_pos = (row, col);
BlockType::Robot
},
_ => {
let mut tmp = [0u8; 4];
let your_string = (grid_str[i] as char).encode_utf8(&mut tmp);
panic!("{}", your_string);
}
};
i += 1;
}
let instructions_str = split.1.trim_ascii().as_bytes();
let mut i = 0;
let mut newlines = 0;
let mut instructions = [InstructionType::Up; INSTRUCTIONS_COUNT * INSTRUCTIONS_LENGTH];
while i < instructions_str.len() {
if instructions_str[i] == b'\n' {
newlines += 1;
i += 1;
continue;
}
instructions[i - newlines] = match instructions_str[i] {
b'^' => InstructionType::Up,
b'v' => InstructionType::Down,
b'<' => InstructionType::Left,
b'>' => InstructionType::Right,
_ => {
let mut tmp = [0u8; 4];
let your_string = (grid_str[i] as char).encode_utf8(&mut tmp);
panic!("{}", your_string);
}
};
i += 1;
}
((grid, robot_pos), instructions)
};
fn main() {
let ((mut grid, mut robot_pos), instructions) = INPUT;
for instruction in instructions {
let mut next = match instruction {
InstructionType::Up => (robot_pos.0 - 1, robot_pos.1),
InstructionType::Down => (robot_pos.0 + 1, robot_pos.1),
InstructionType::Left => (robot_pos.0, robot_pos.1 - 1),
InstructionType::Right => (robot_pos.0, robot_pos.1 + 1)
};
match grid[next.0][next.1] {
// Can't do anything if next is a wall
BlockType::Wall => continue,
// If empty, shrimply move there
BlockType::Empty => {
grid[robot_pos.0][robot_pos.1] = BlockType::Empty;
grid[next.0][next.1] = BlockType::Robot;
robot_pos = next;
},
// Wtf
BlockType::Robot => unreachable!(),
// Do box pusher logic
BlockType::Box => {
let original_box = next;
// Loop until we find a place to put the box
let mut failed = false;
loop {
next = match instruction {
InstructionType::Up => (next.0 - 1, next.1),
InstructionType::Down => (next.0 + 1, next.1),
InstructionType::Left => (next.0, next.1 - 1),
InstructionType::Right => (next.0, next.1 + 1)
};
// Overflow impossible, breaks on wall
match grid[next.0][next.1] {
BlockType::Wall => {
failed = true;
break;
},
BlockType::Box => continue,
BlockType::Empty => break,
BlockType::Robot => unreachable!(),
}
}
if !failed {
// Move robot to box location
grid[original_box.0][original_box.1] = BlockType::Robot;
grid[robot_pos.0][robot_pos.1] = BlockType::Empty;
robot_pos = original_box;
// Put box in empty slot
grid[next.0][next.1] = BlockType::Box;
}
},
}
}
let mut sum = 0_usize;
for row in 0..GRID_SIZE {
for col in 0..GRID_SIZE {
if grid[row][col] != BlockType::Box { continue }
sum += 100 * row + col;
}
}
println!("Result: {sum}")
}

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@ -20,11 +20,11 @@
},
"nixpkgs": {
"locked": {
"lastModified": 1733759999,
"narHash": "sha256-463SNPWmz46iLzJKRzO3Q2b0Aurff3U1n0nYItxq7jU=",
"lastModified": 1734119587,
"narHash": "sha256-AKU6qqskl0yf2+JdRdD0cfxX4b9x3KKV5RqA6wijmPM=",
"owner": "NixOS",
"repo": "nixpkgs",
"rev": "a73246e2eef4c6ed172979932bc80e1404ba2d56",
"rev": "3566ab7246670a43abd2ffa913cc62dad9cdf7d5",
"type": "github"
},
"original": {
@ -62,11 +62,11 @@
"nixpkgs": "nixpkgs_2"
},
"locked": {
"lastModified": 1733884434,
"narHash": "sha256-8GXR9kC07dyOIshAyfZhG11xfvBRSZzYghnZ2weOKJU=",
"lastModified": 1734402816,
"narHash": "sha256-cgQ8mjUJz7J3fp97lnvl0dSJ6vLt8yzUSmw3B7QKw94=",
"owner": "oxalica",
"repo": "rust-overlay",
"rev": "d0483df44ddf0fd1985f564abccbe568e020ddf2",
"rev": "e38fbd6e56e8cd1d61c65a21bbb7785e966707b4",
"type": "github"
},
"original": {

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@ -19,6 +19,7 @@
extensions = [ "rust-src" "rustfmt" ];
targets = [ "x86_64-unknown-linux-gnu" ];
}))
evcxr
];
};
});