drakeerv day 15 & 16 (#79)

Author: drakeerv

2024/15/drakeerv.v

@@ -0,0 +1,271 @@
+import os
+import arrays
+
+enum Tile {
+	wall
+	box1
+	box2
+	empty
+}
+
+struct Vector {
+pub:
+	// Change to immutable
+	x int
+	y int
+}
+
+fn (v Vector) update(other Vector) Vector {
+	return Vector{other.x, other.y}
+}
+
+fn (v Vector) add(other Vector) Vector {
+	return Vector{v.x + other.x, v.y + other.y}
+}
+
+fn (v Vector) sub(other Vector) Vector {
+	return Vector{v.x - other.x, v.y - other.y}
+}
+
+fn (v Vector) mul(other Vector) Vector {
+	return Vector{v.x * other.x, v.y * other.y}
+}
+
+fn (v Vector) eq(other Vector) bool {
+	return v.x == other.x && v.y == other.y
+}
+
+fn (v Vector) clone() Vector {
+	return Vector{v.x, v.y}
+}
+
+fn get_tile(grid [][]Tile, position Vector) Tile {
+	return grid[position.y][position.x]
+}
+
+fn set_tile(mut grid [][]Tile, position Vector, tile Tile) {
+	grid[position.y][position.x] = tile
+}
+
+fn parse_map_tile(c string) Tile {
+	return match c {
+		'#' { Tile.wall }
+		'O' { Tile.box1 }
+		'.' { Tile.empty }
+		'@' { Tile.empty }
+		else { panic('Invalid tile character: ${c}') }
+	}
+}
+
+fn parse_movement(c string) Vector {
+	return match c {
+		'v' { Vector{0, 1} }
+		'^' { Vector{0, -1} }
+		'<' { Vector{-1, 0} }
+		'>' { Vector{1, 0} }
+		else { panic('Invalid movement character: ${c}') }
+	}
+}
+
+fn find_both_boxes(grid [][]Tile, position Vector) []Vector {
+	tile := get_tile(grid, position)
+	if tile == .box1 {
+		mut box2_pos := position.clone()
+		box2_pos = box2_pos.add(Vector{1, 0})
+		return [position, box2_pos]
+	} else if tile == .box2 {
+		mut box1_pos := position.clone()
+		box1_pos = box1_pos.add(Vector{-1, 0})
+		return [box1_pos, position]
+	}
+	panic('Invalid box position')
+}
+
+fn is_movable_y(grid [][]Tile, position Vector, movement Vector) bool {
+	tile := get_tile(grid, position)
+	if tile == .wall {
+		return false
+	} else if tile == .empty {
+		return true
+	}
+
+	// Find both boxes and check if they can move
+	boxes := find_both_boxes(grid, position)
+	mut next_box1_pos := boxes[0].clone()
+	mut next_box2_pos := boxes[1].clone()
+	next_box1_pos = next_box1_pos.add(movement)
+	next_box2_pos = next_box2_pos.add(movement)
+
+	return is_movable_y(grid, next_box1_pos, movement)
+		&& is_movable_y(grid, next_box2_pos, movement)
+}
+
+fn move_box_y(mut grid [][]Tile, box1_pos Vector, movement Vector) {
+	next_left_pos := box1_pos.add(movement)
+	next_right_pos := next_left_pos.add(Vector{1, 0})
+	next_left_tile := get_tile(grid, next_left_pos)
+	next_right_tile := get_tile(grid, next_right_pos)
+
+	if next_left_tile == .box1 {
+		move_box_y(mut grid, next_left_pos, movement)
+	} else if next_left_tile == .box2 {
+		move_box_y(mut grid, next_left_pos.add(Vector{-1, 0}), movement)
+	}
+
+	if next_right_tile == .box1 {
+		move_box_y(mut grid, next_right_pos, movement)
+	}
+
+	set_tile(mut grid, next_left_pos, .box1)
+	set_tile(mut grid, next_right_pos, .box2)
+	set_tile(mut grid, box1_pos, .empty)
+	set_tile(mut grid, box1_pos.add(Vector{1, 0}), .empty)
+}
+
+fn is_movable_x(grid [][]Tile, position Vector, movement Vector) ?Vector {
+	tile := get_tile(grid, position)
+	if tile == .wall {
+		return none
+	} else if tile == .empty {
+		return position
+	}
+
+	if tile == .box1 {
+		return is_movable_x(grid, position.add(Vector{2, 0}), movement)
+	} else if tile == .box2 {
+		return is_movable_x(grid, position.add(Vector{-2, 0}), movement)
+	}
+	return none
+}
+
+fn main() {
+	data := os.read_file('movements.input')!.replace('\r', '').split('\n')
+	separation := data.index('')
+
+	// Parse the grid
+	mut grid := [][]Tile{}
+	for row in data[..separation] {
+		grid << row.split('').map(parse_map_tile)
+	}
+
+	// Find robot position
+	mut robot := Vector{0, 0}
+	for y, row in data[..separation] {
+		x := row.index('@') or { continue }
+		robot = Vector{int(x), y}
+		break
+	}
+
+	// Parse movements
+	movements := data[separation + 1..].filter(it != '').join('').split('').map(parse_movement)
+
+	// PART 1
+	mut robot1 := robot.clone()
+	mut grid1 := [][]Tile{len: grid.len, init: grid[index].clone()}
+
+	// Execute movements
+	for movement in movements {
+		mut next_robot_position := robot1.clone()
+		next_robot_position = next_robot_position.add(movement)
+		next_robot_tile := get_tile(grid1, next_robot_position)
+
+		if next_robot_tile == .wall {
+			continue
+		}
+
+		if next_robot_tile == .box1 {
+			mut next_box_position := next_robot_position.clone()
+			next_box_position = next_box_position.add(movement)
+			mut next_box_tile := get_tile(grid1, next_box_position)
+
+			for next_box_tile == .box1 {
+				next_box_position = next_box_position.add(movement)
+				next_box_tile = get_tile(grid1, next_box_position)
+			}
+
+			if next_box_tile == .wall {
+				continue
+			}
+
+			set_tile(mut grid1, next_box_position, .box1)
+			set_tile(mut grid1, next_robot_position, .empty)
+		}
+
+		robot1 = robot1.update(next_robot_position)
+	}
+
+	// Calculate part 1
+	mut part1 := 0
+	for y, row in grid1 {
+		for x, tile in row {
+			if tile == .box1 {
+				part1 += (y * 100) + x
+			}
+		}
+	}
+	println('part1: ${part1}')
+
+	// PART 2
+	mut robot2 := robot.clone()
+	robot2 = robot2.mul(Vector{2, 1})
+
+	mut grid2 := [][]Tile{}
+	for row in grid {
+		mut row_tiles := [][]Tile{}
+		for tile in row {
+			if tile == .box1 {
+				row_tiles << [Tile.box1, Tile.box2]
+			} else {
+				row_tiles << [tile, tile]
+			}
+		}
+		grid2 << arrays.flatten[Tile](row_tiles)
+	}
+
+	// Execute movements for part 2
+	for movement in movements {
+		next_robot_position := robot2.add(movement)
+		next_robot_tile := get_tile(grid2, next_robot_position)
+
+		if next_robot_tile == .wall {
+			continue
+		}
+
+		if next_robot_tile in [.box1, .box2] {
+			if movement.x == 0 {
+				// Vertical movement logic
+				if !is_movable_y(grid2, next_robot_position, movement) {
+					continue
+				}
+				boxes := find_both_boxes(grid2, next_robot_position)
+				move_box_y(mut grid2, boxes[0], movement)
+			} else {
+				// Horizontal movement logic
+				next_box_pos := is_movable_x(grid2, next_robot_position, movement) or { continue }
+
+				mut next_box_move_pos := next_box_pos
+				mut next_box_tile := get_tile(grid2, next_box_move_pos.sub(movement))
+				set_tile(mut grid2, next_box_pos, next_box_tile)
+
+				for next_box_tile != .empty {
+					next_box_move_pos = next_box_move_pos.sub(movement)
+					next_box_tile = get_tile(grid2, next_box_move_pos.sub(movement))
+					set_tile(mut grid2, next_box_move_pos, next_box_tile)
+				}
+			}
+		}
+
+		robot2 = robot2.update(next_robot_position)
+	}
+
+	// Calculate part 2
+	mut part2 := 0
+	for y, row in grid2 {
+		for x, tile in row {
+			if tile == .box1 {
+				part2 += (y * 100) + x
+			}
+		}
+	}
+	println('part2: ${part2}')
+}

2024/15/movements.input

@@ -0,0 +1,21 @@
+##########
+#..O..O.O#
+#......O.#
+#.OO..O.O#
+#[email protected].#
+#O#..O...#
+#O..O..O.#
+#.OO.O.OO#
+#....O...#
+##########
+
+<vv>^<v^>v>^vv^v>v<>v^v<v<^vv<<<^><<><>>v<vvv<>^v^>^<<<><<v<<<v^vv^v>^
+vvv<<^>^v^^><<>>><>^<<><^vv^^<>vvv<>><^^v>^>vv<>v<<<<v<^v>^<^^>>>^<v<v
+><>vv>v^v^<>><>>>><^^>vv>v<^^^>>v^v^<^^>v^^>v^<^v>v<>>v^v^<v>v^^<^^vv<
+<<v<^>>^^^^>>>v^<>vvv^><v<<<>^^^vv^<vvv>^>v<^^^^v<>^>vvvv><>>v^<<^^^^^
+^><^><>>><>^^<<^^v>>><^<v>^<vv>>v>>>^v><>^v><<<<v>>v<v<v>vvv>^<><<>^><
+^>><>^v<><^vvv<^^<><v<<<<<><^v<<<><<<^^<v<^^^><^>>^<v^><<<^>>^v<v^v<v^
+>^>>^v>vv>^<<^v<>><<><<v<<v><>v<^vv<<<>^^v^>^^>>><<^v>>v^v><^^>>^<>vv^
+<><^^>^^^<><vvvvv^v<v<<>^v<v>v<<^><<><<><<<^^<<<^<<>><<><^^^>^^<>^>v<>
+^^>vv<^v^v<vv>^<><v<^v>^^^>>>^^vvv^>vvv<>>>^<^>>>>>^<<^v>^vvv<>^<><<v>
+v^^>>><<^^<>>^v^<v^vv<>v^<<>^<^v^v><^<<<><<^<v><v<>vv>>v><v^<vv<>v^<<^