day 15

Cargo.lock

@@ -71,6 +71,13 @@ dependencies = [
 name = "day14"
 version = "0.1.0"
 
+[[package]]
+name = "day15"
+version = "0.1.0"
+dependencies = [
+ "shared 0.1.0",
+]
+
 [[package]]
 name = "day2"
 version = "0.1.0"

Cargo.toml

@@ -14,5 +14,6 @@ members = [
 	"day12",
 	"day13",
 	"day14",
+	"day15",
 	"shared",
 ]

day15/Cargo.toml

@@ -0,0 +1,10 @@
+[package]
+name = "day15"
+version = "0.1.0"
+authors = ["Stefan Bühler <stbuehler@web.de>"]
+edition = "2018"
+
+# See more keys and their definitions at https://doc.rust-lang.org/cargo/reference/manifest.html
+
+[dependencies]
+shared = { path = "../shared" }

day15/src/input.txt

@@ -0,0 +1 @@
+3,1033,1008,1033,1,1032,1005,1032,31,1008,1033,2,1032,1005,1032,58,1008,1033,3,1032,1005,1032,81,1008,1033,4,1032,1005,1032,104,99,101,0,1034,1039,101,0,1036,1041,1001,1035,-1,1040,1008,1038,0,1043,102,-1,1043,1032,1,1037,1032,1042,1105,1,124,102,1,1034,1039,101,0,1036,1041,1001,1035,1,1040,1008,1038,0,1043,1,1037,1038,1042,1105,1,124,1001,1034,-1,1039,1008,1036,0,1041,1002,1035,1,1040,1002,1038,1,1043,1001,1037,0,1042,1105,1,124,1001,1034,1,1039,1008,1036,0,1041,1002,1035,1,1040,101,0,1038,1043,101,0,1037,1042,1006,1039,217,1006,1040,217,1008,1039,40,1032,1005,1032,217,1008,1040,40,1032,1005,1032,217,1008,1039,35,1032,1006,1032,165,1008,1040,33,1032,1006,1032,165,1102,2,1,1044,1106,0,224,2,1041,1043,1032,1006,1032,179,1101,1,0,1044,1106,0,224,1,1041,1043,1032,1006,1032,217,1,1042,1043,1032,1001,1032,-1,1032,1002,1032,39,1032,1,1032,1039,1032,101,-1,1032,1032,101,252,1032,211,1007,0,27,1044,1105,1,224,1101,0,0,1044,1105,1,224,1006,1044,247,101,0,1039,1034,1002,1040,1,1035,101,0,1041,1036,1001,1043,0,1038,101,0,1042,1037,4,1044,1106,0,0,8,86,20,11,8,18,84,20,96,25,15,28,96,20,74,24,7,5,77,6,77,6,23,74,3,23,93,21,72,23,1,57,87,10,17,9,23,48,16,9,32,11,62,73,5,70,2,10,77,23,16,76,24,28,13,46,92,26,15,10,87,13,28,54,10,50,4,16,47,75,24,55,4,99,92,17,66,24,7,13,33,43,21,65,24,4,74,40,8,28,25,5,72,25,5,54,19,72,6,44,49,3,65,11,24,85,39,11,5,77,15,6,65,12,66,66,14,8,88,81,2,8,99,7,54,70,2,97,69,9,17,51,47,1,56,88,81,41,10,98,16,23,35,24,82,24,5,99,39,67,8,14,46,56,5,8,59,9,53,9,21,95,6,95,7,12,85,26,79,82,19,21,62,99,5,13,81,19,31,15,29,67,45,22,75,84,14,25,83,33,97,4,85,15,17,25,21,51,55,11,76,32,15,43,60,13,13,11,65,65,16,9,96,26,17,10,94,23,12,37,16,49,2,81,17,11,20,17,16,37,87,16,12,96,23,10,68,22,75,34,4,22,14,34,14,62,8,34,12,72,7,40,5,54,10,89,7,96,1,14,72,7,11,60,93,68,51,21,86,25,34,26,20,38,7,21,94,78,10,8,46,4,81,12,84,30,11,9,48,12,83,73,42,83,26,26,40,22,91,6,38,99,2,40,24,93,10,22,84,22,19,94,8,6,42,33,11,15,31,66,33,2,65,39,67,26,5,67,19,86,1,12,20,28,54,80,84,3,17,32,26,51,8,6,20,67,15,54,30,5,31,97,9,10,29,18,45,8,23,69,18,61,11,4,73,5,46,13,96,16,80,66,17,1,11,50,37,4,34,94,15,32,77,5,93,69,12,66,6,24,18,84,26,42,5,78,74,22,82,15,23,60,11,64,61,59,48,11,99,49,3,68,2,16,14,99,7,94,9,22,75,20,30,21,17,91,20,41,21,26,42,44,19,18,85,17,96,21,2,88,62,69,8,39,3,11,62,12,25,29,69,79,52,56,6,52,22,78,42,8,18,22,59,91,13,94,89,10,16,73,11,17,80,81,26,36,26,55,16,13,30,6,6,43,1,43,83,21,69,11,42,8,77,21,31,25,24,99,26,56,85,15,74,1,88,13,3,18,42,14,54,13,6,91,49,7,36,42,2,8,67,55,14,35,5,33,6,96,24,94,24,59,46,18,4,61,95,2,33,33,2,31,24,97,1,91,15,52,15,53,44,10,20,47,93,8,1,48,80,22,80,23,15,92,18,18,59,19,69,17,8,55,38,26,9,68,23,85,2,12,23,77,4,21,16,6,90,45,17,61,16,28,22,24,58,30,26,2,85,1,53,29,18,37,30,38,4,12,92,60,19,13,56,19,85,7,66,19,73,39,9,90,81,3,8,9,72,25,37,24,5,96,25,13,81,92,34,19,95,3,26,36,25,25,25,15,95,6,35,43,92,10,79,70,8,30,18,96,75,1,5,76,17,86,3,46,22,11,50,96,1,56,43,2,23,53,7,71,20,61,73,34,31,57,24,69,4,24,6,25,98,50,21,63,12,97,11,9,72,19,40,21,7,2,18,77,83,16,1,82,24,25,57,72,25,9,15,76,21,14,71,16,94,7,64,21,69,87,18,65,1,21,20,61,91,10,86,7,55,36,1,40,99,39,8,41,5,92,76,33,20,40,15,81,76,48,5,35,64,59,6,30,13,52,19,84,21,58,1,89,29,53,10,76,22,33,26,65,3,96,0,0,21,21,1,10,1,0,0,0,0,0,0

day15/src/main.rs

@@ -0,0 +1,267 @@
+use shared::intcode::{IntCode, CELL};
+use std::collections::HashMap;
+
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
+pub enum Cell {
+	Unknown,
+	Wall,
+	Empty,
+}
+
+impl Default for Cell {
+	fn default() -> Self {
+		Self::Unknown
+	}
+}
+
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
+#[repr(u8)]
+pub enum Direction {
+	North = 1,
+	South = 2,
+	West = 3,
+	East = 4,
+}
+
+impl Direction {
+	fn all() -> impl Iterator<Item=Self> {
+		[
+			Self::North,
+			Self::South,
+			Self::West,
+			Self::East,
+		].iter().cloned()
+	}
+}
+
+#[derive(Clone, Copy, PartialEq, Eq, PartialOrd, Ord, Hash, Debug)]
+pub struct Position {
+	x: usize,
+	y: usize,
+}
+
+impl Position {
+	fn go(self, field: &Field, d: Direction) -> Option<Self> {
+		match d {
+			Direction::North => {
+				if self.y > 0 { return Some(Position { x: self.x, y: self.y - 1}); }
+			},
+			Direction::South => {
+				if self.y + 1 < field.cells.len() { return Some(Position { x: self.x, y: self.y + 1 }); }
+			},
+			Direction::West => {
+				if self.x > 0 { return Some(Position { x: self.x - 1, y: self.y }); }
+			},
+			Direction::East => {
+				if self.x + 1 < field.columns { return Some(Position { x: self.x + 1, y: self.y }); }
+			},
+		}
+		None
+	}
+}
+
+pub struct Field {
+	ic: IntCode,
+	columns: usize,
+	cells: Vec<Vec<Cell>>,
+	robot: Position,
+	start: Position,
+	oxygen: Option<Position>,
+}
+
+impl Field {
+	pub fn new(ic: IntCode) -> Self {
+		Self {
+			ic,
+			columns: 3,
+			cells: vec![
+				vec![Cell::Unknown, Cell::Unknown, Cell::Unknown],
+				vec![Cell::Unknown, Cell::Empty, Cell::Unknown],
+				vec![Cell::Unknown, Cell::Unknown, Cell::Unknown],
+			],
+			robot: Position { x: 1, y: 1 },
+			start: Position { x: 1, y: 1 },
+			oxygen: None,
+		}
+	}
+
+	fn prepend_row(&mut self) {
+		let mut row = Vec::new();
+		row.resize(self.columns, Cell::Unknown);
+		self.cells.insert(0, row);
+		self.robot.y += 1;
+		self.start.y += 1;
+		if let Some(oxygen) = &mut self.oxygen { oxygen.y += 1; }
+	}
+
+	fn append_row(&mut self) {
+		let mut row = Vec::new();
+		row.resize(self.columns, Cell::Unknown);
+		self.cells.push(row);
+	}
+
+	fn prepend_col(&mut self) {
+		self.columns += 1;
+		for row in &mut self.cells {
+			row.insert(0, Cell::Unknown);
+		}
+		self.robot.x += 1;
+		self.start.x += 1;
+		if let Some(oxygen) = &mut self.oxygen { oxygen.x += 1; }
+	}
+
+	fn append_col(&mut self) {
+		self.columns += 1;
+		for row in &mut self.cells {
+			row.push(Cell::Unknown);
+		}
+	}
+
+	fn set_cell(&mut self, pos: Position, cell: Cell) {
+		self.cells[pos.y][pos.x] = cell;
+		if pos.y == 0 { self.prepend_row(); }
+		if pos.y + 1 == self.cells.len() { self.append_row(); }
+		if pos.x == 0 { self.prepend_col(); }
+		if pos.x + 1 == self.columns { self.append_col(); }
+	}
+
+	fn cell(&self, pos: Position) -> Cell {
+		self.cells[pos.y][pos.x]
+	}
+
+	// returns whether robot moved (false: hit wall)
+	fn robot_walk(&mut self, direction: Direction) -> bool {
+		assert!(self.ic.next_input.is_none());
+		self.ic.next_input = Some((direction as u8) as CELL);
+		let next_pos = self.robot.go(self, direction).expect("invalid direction in current field");
+		match self.ic.simulate_step().expect_output() {
+			0 => {
+				self.set_cell(next_pos, Cell::Wall);
+				false
+			},
+			1 => {
+				self.robot = next_pos; // set_cell might update this
+				self.set_cell(next_pos, Cell::Empty);
+				true
+			},
+			2 => {
+				self.robot = next_pos; // set_cell might update this
+				self.set_cell(next_pos, Cell::Empty);
+				self.oxygen = Some(self.robot);
+				true
+			},
+			_ => panic!("Invalid IC output"),
+		}
+	}
+
+	// if it can't find a path, return maximum pathlen for shortest path to a reachable cell
+	fn find_path<F>(&self, start: Position, is_target: F, unknown_ok: bool) -> Result<Vec<Direction>, usize>
+	where
+		F: Fn(Position) -> bool,
+	{
+		// sad simulation of a "min-priority queue" - but our problem is small enough.
+		let mut border: HashMap<Position, usize> = HashMap::new();
+		// for traversing found path in the end
+		let mut known: HashMap<Position, Option<(Position, Direction)>> = HashMap::new();
+		let mut max_path_len = 0;
+		if is_target(start) { return Ok(vec![]); }
+		known.insert(start, None);
+		border.insert(start, 0);
+		let target;
+		'outer: loop {
+			if border.is_empty() { return Err(max_path_len); }
+			let source = *border.iter().min_by_key(|(_k, v)| *v).unwrap().0;
+			let next_pathlen = border.remove(&source).unwrap() + 1;
+			for d in Direction::all() {
+				if let Some(next) = source.go(self, d) {
+					if known.contains_key(&next) { continue; }
+					match self.cell(next) {
+						Cell::Wall => continue,
+						Cell::Unknown => if !unknown_ok { continue; },
+						Cell::Empty => (),
+					}
+					known.insert(next, Some((source, d)));
+					if is_target(next) { target = next; break 'outer; }
+					border.insert(next, next_pathlen);
+					max_path_len = max_path_len.max(next_pathlen);
+				}
+			}
+		}
+
+		let mut path = Vec::new();
+		let mut current = target;
+		loop {
+			let (previous, d) = match &known[&current] {
+				Some((p, d)) => (*p, *d),
+				None => break,
+			};
+			path.push(d);
+			current = previous;
+		}
+		path.reverse();
+		Ok(path)
+	}
+
+	fn draw(&self) {
+		for (y, row) in self.cells.iter().enumerate() {
+			for (x, cell) in row.iter().enumerate() {
+				let pos = Position { x, y };
+				if Some(pos) == self.oxygen {
+					print!("O");
+				} else if pos == self.robot {
+					print!("D");
+				} else if pos == self.start {
+					print!("X");
+				} else {
+					match cell {
+						Cell::Unknown => print!("⋅"),
+						Cell::Wall => print!("#"),
+						Cell::Empty => print!(" "),
+					}
+				}
+			}
+			println!("");
+		}
+		println!("-");
+	}
+
+	pub fn find_oxygen(&mut self) -> usize {
+		let mut path = Vec::new();
+		loop {
+			// if self.oxygen.is_some() { break; }
+			if path.is_empty() {
+				path = match self.find_path(self.robot, |pos| {
+					self.cell(pos) == Cell::Unknown
+				}, true) {
+					Ok(path) => path,
+					Err(_) => break,
+				};
+			}
+			let d = path.remove(0);
+			if !self.robot_walk(d) { path.clear(); } // need new path when hitting a wall
+			self.draw();
+		}
+		self.find_path(self.start, |pos| Some(pos) == self.oxygen, false).expect("no path to oxygen system").len()
+	}
+}
+
+fn main() {
+	let ic = include_str!("input.txt").parse::<IntCode>().unwrap();
+	let mut field = Field::new(ic);
+	field.draw();
+	println!("Oxygen sytsem is {} moves away", field.find_oxygen());
+	println!("Oxygen distributed after {} minutes", field.find_path(field.oxygen.unwrap(), |_| false, false).unwrap_err());
+}
+
+#[cfg(test)]
+mod day15test {
+	#[test]
+	fn examples1() {
+		// no runnable tests
+	}
+
+	#[test]
+	fn examples2() {
+		// no runnable tests
+	}
+}