AoC 2024 Day 15 Part 1

Author: pareronia

src/main/python/AoC2024_15.py

@@ -0,0 +1,168 @@
+#! /usr/bin/env python3
+#
+# Advent of Code 2024 Day 15
+#
+
+import sys
+
+from aoc import my_aocd
+from aoc.common import InputData
+from aoc.common import SolutionBase
+from aoc.common import aoc_samples, log
+from aoc.geometry import Direction
+from aoc.grid import CharGrid
+from aoc.grid import Cell
+
+Input = tuple[CharGrid, list[Direction]]
+Output1 = int
+Output2 = int
+
+
+TEST1 = """\
+########
+#..O.O.#
+##@.O..#
+#...O..#
+#.#.O..#
+#...O..#
+#......#
+########
+
+<^^>>>vv<v>>v<<
+"""
+TEST2 = """\
+##########
+#..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^<<^
+"""
+
+
+class Solution(SolutionBase[Input, Output1, Output2]):
+    def print_grid(self, grid: CharGrid) -> None:
+        for line in grid.get_rows_as_strings():
+            log(line)
+
+    def parse_input(self, input_data: InputData) -> Input:
+        blocks = my_aocd.to_blocks(input_data)
+        grid = CharGrid.from_strings(blocks[0])
+        dirs = list[Direction]()
+        for line in blocks[1]:
+            dirs.extend([Direction.from_str(ch) for ch in line])
+        return grid, dirs
+
+    def part_1(self, input: Input) -> Output1:
+        def move(line: list[str], r: int) -> list[str]:
+            def swap(line: list[str], idx1: int, idx2: int) -> list[str]:
+                tmp = line[idx1]
+                line[idx1] = line[idx2]
+                line[idx2] = tmp
+                return line
+
+            assert line[r] == "@"
+            if line[r + 1] == "#":
+                return line
+            # max_idx = len(line) - 2
+            # #[email protected]....#  -> #.....@O....#
+            if line[r + 1] == ".":
+                line = swap(line, r, r + 1)
+            # #.....@O....#  -> #......@O...#
+            try:
+                dot_idx = line.index(".", r)
+                octo_idx = line.index("#", r)
+                if dot_idx < octo_idx:
+                    line.pop(dot_idx)
+                    line.insert(r, ".")
+            except ValueError:
+                return line
+            return line
+
+        def to_array(s: str) -> list[str]:
+            return [ch for ch in s]
+
+        def to_str(a: list[str]) -> str:
+            return "".join(a)
+
+        assert to_str(move(to_array("#..@#"), 3)) == "#..@#"
+        assert to_str(move(to_array("#[email protected]....#"), 5)) == "#.....@O....#"  # noqa E501
+        assert to_str(move(to_array("#.....@O....#"), 6)) == "#......@O...#"  # noqa E501
+        assert to_str(move(to_array("#..@O#"), 3)) == "#..@O#"  # noqa E501
+        assert to_str(move(to_array("#[email protected].#"), 2)) == "#..@OO.#"  # noqa E501
+        assert to_str(move(to_array("#.#@O..#"), 3)) == "#.#.@O.#"  # noqa E501
+        assert to_str(move(to_array("#.@O#..#"), 2)) == "#.@O#..#"  # noqa E501
+        grid, dirs = input
+        # self.print_grid(grid)
+        # log(dirs)
+        robot = next(grid.get_all_equal_to("@"))
+        for dir in dirs:
+            match dir:
+                case Direction.RIGHT:
+                    row = grid.values[robot.row]
+                    tmp = move(row, robot.col)
+                    grid.values[robot.row] = tmp
+                    robot = Cell(robot.row, tmp.index("@"))
+                case Direction.LEFT:
+                    row = grid.values[robot.row]
+                    row.reverse()
+                    tmp = move(row, row.index("@"))
+                    tmp.reverse()
+                    grid.values[robot.row] = tmp
+                    robot = Cell(robot.row, tmp.index("@"))
+                case Direction.DOWN:
+                    col = grid.get_col(robot.col)
+                    tmp = move(col, robot.row)
+                    grid.replace_col(robot.col, tmp)
+                    robot = Cell(tmp.index("@"), robot.col)
+                case Direction.UP:
+                    col = grid.get_col(robot.col)
+                    col.reverse()
+                    tmp = move(col, col.index("@"))
+                    tmp.reverse()
+                    grid.replace_col(robot.col, tmp)
+                    robot = Cell(tmp.index("@"), robot.col)
+            # self.print_grid(grid)
+        ans = 0
+        for cell in grid.get_all_equal_to("O"):
+            ans += cell.row * 100 + cell.col
+        return ans
+
+    def part_2(self, input: Input) -> Output2:
+        return 0
+
+    @aoc_samples(
+        (
+            ("part_1", TEST1, 2028),
+            ("part_1", TEST2, 10092),
+            # ("part_2", TEST1, "TODO"),
+        )
+    )
+    def samples(self) -> None:
+        pass
+
+
+solution = Solution(2024, 15)
+
+
+def main() -> None:
+    solution.run(sys.argv)
+
+
+if __name__ == "__main__":
+    main()

src/main/python/aoc/grid.py

@@ -143,6 +143,14 @@ def set_value(self, c: Cell, value: T) -> None:
     def get_row_as_string(self, row: int) -> str:
         pass
 
+    @abstractmethod
+    def get_col(self, col: int) -> list[T]:
+        pass
+
+    @abstractmethod
+    def replace_col(self, col: int, val: list[T]) -> None:
+        pass
+
     def size(self) -> int:
         return self.get_height() * self.get_width()
 
@@ -264,6 +272,12 @@ def increment(self, c: Cell) -> None:
     def get_row_as_string(self, row: int) -> str:
         return "".join(str(_) for _ in self.values[row])
 
+    def get_col(self, col: int) -> list[int]:
+        raise NotImplementedError
+
+    def replace_col(self, col: int, val: list[int]) -> None:
+        raise NotImplementedError
+
 
 @dataclass(frozen=True)
 class CharGrid(Grid[str]):
@@ -295,6 +309,14 @@ def set_value(self, c: Cell, value: str) -> None:
     def get_row_as_string(self, row: int) -> str:
         return "".join(self.values[row])
 
+    def get_col(self, col: int) -> list[str]:
+        return [self.values[row][col] for row in range(self.get_height())]
+
+    def replace_col(self, col: int, val: list[str]) -> None:
+        assert len(val) == self.get_height()
+        for row in range(self.get_height()):
+            self.values[row][col] = val[row]
+
     def get_col_as_string(self, col: int) -> str:
         return "".join(
             self.values[row][col] for row in range(self.get_height())

src/test/python/test_grid.py

@@ -108,6 +108,20 @@ def test_roll_column(self) -> None:
             grid, CharGrid.from_strings(["#.#....", "###....", ".#....."])
         )
 
+    def test_get_col(self) -> None:
+        grid = CharGrid.from_strings(["ABC", "DEF", "GHI"])
+
+        col = grid.get_col(1)
+
+        self.assertEqual(col, ["B", "E", "H"])
+
+    def test_replace_col(self) -> None:
+        grid = CharGrid.from_strings(["ABC", "DEF", "GHI"])
+
+        grid.replace_col(1, ["X", "X", "X"])
+
+        self.assertEqual(grid, CharGrid.from_strings(["AXC", "DXF", "GXI"]))
+
 
 class IntGridIteratorTest(unittest.TestCase):