Added day 6 for 2024

2024/src/day05.py

@@ -1,4 +1,3 @@
-import re
 import sys
 from inputs import load_input
 

2024/src/day06.py

@@ -0,0 +1,144 @@
+import copy
+import sys
+from inputs import load_input
+
+
+def part1() -> int:
+    input_strings = load_input("./input/day06")
+    grid = create_grid(input_strings)
+    starting_position = get_starting_position(input_strings)
+    traversed_tiles = get_traversed_tiles(starting_position, grid)
+    return len(set(traversed_tiles))
+
+
+def part2() -> int:
+    input_strings = load_input("./input/day06")
+    grid = create_grid(input_strings)
+    starting_position = get_starting_position(input_strings)
+    sum = traverse_while_introducing_blockers(starting_position, (-1, 0), grid)
+    return sum
+
+
+def create_grid(input_strings: list[str]) -> list[list[bool]]:
+    grid = []
+    for y in range(len(input_strings)):
+        row = []
+        input_row = input_strings[y].strip()
+        for x in range(len(input_row)):
+            if input_strings[y][x] == "#":
+                row.append(False)
+            else:
+                row.append(True)
+        grid.append(row)
+    return grid
+
+
+def get_starting_position(input_strings: list[str]) -> tuple[int, int]:
+    for y in range(len(input_strings)):
+        for x in range(len(input_strings[y])):
+            if input_strings[y][x] == "^":
+                return (y, x)
+    raise RuntimeError("Starting position not found")
+
+
+def get_traversed_tiles(
+    starting_position: tuple[int, int], grid: list[list[bool]]
+) -> list[tuple[int, int]]:
+    current_position = starting_position
+    traversed_tiles = [starting_position]
+    vector = (-1, 0)
+    while not out_of_bounds(current_position, vector, grid):
+        next_position = calculate_next_position(current_position, vector, grid)
+        if current_position != next_position:
+            current_position = next_position
+            traversed_tiles.append(next_position)
+        else:
+            vector = rotate_vector(vector)
+    return traversed_tiles
+
+
+def calculate_next_position(
+    current_position: tuple[int, int], vector: tuple[int, int], grid: list[list[bool]]
+) -> tuple[int, int]:
+    continued_vector = add_tuple(current_position, vector)
+    if get_tile(continued_vector, grid):
+        current_position = continued_vector
+    return current_position
+
+
+def traverse_while_introducing_blockers(
+    starting_position: tuple[int, int],
+    start_vector: tuple[int, int],
+    grid: list[list[bool]],
+) -> int:
+    traversed_tiles = set(get_traversed_tiles(starting_position, grid))
+    traversed_tiles.remove(starting_position)
+    sum = 0
+    for each in traversed_tiles:
+        new_grid = introduce_blocker(each, grid)
+        can_be_blocked = traverse_with_loop_check(
+            starting_position, start_vector, new_grid
+        )
+        if can_be_blocked:
+            sum += 1
+    return sum
+
+
+def introduce_blocker(
+    blocker_position: tuple[int, int], grid: list[list[bool]]
+) -> list[list[bool]]:
+    new_grid = copy.deepcopy(grid)
+    new_grid[blocker_position[0]][blocker_position[1]] = False
+    return new_grid
+
+
+def traverse_with_loop_check(
+    starting_position: tuple[int, int],
+    start_vector: tuple[int, int],
+    grid: list[list[bool]],
+) -> bool:
+    current_position = starting_position
+    vector = start_vector
+    traversed: set[tuple[tuple[int, int], tuple[int, int]]] = set()
+    while not out_of_bounds(current_position, vector, grid):
+        if (current_position, vector) in traversed:
+            return True
+        next_position = calculate_next_position(current_position, vector, grid)
+        if current_position != next_position:
+            traversed.add((current_position, vector))
+            current_position = next_position
+        else:
+            vector = rotate_vector(vector)
+    return False
+
+
+def out_of_bounds(
+    position: tuple[int, int], vector: tuple[int, int], grid: list[list[bool]]
+) -> bool:
+    y_max = len(grid)
+    (y, x) = add_tuple(position, vector)
+    return y < 0 or y >= y_max or x < 0 or x >= len(grid[y])
+
+
+def add_tuple(tuple1: tuple[int, int], tuple2: tuple[int, int]) -> tuple[int, int]:
+    return (tuple1[0] + tuple2[0], tuple1[1] + tuple2[1])
+
+
+def get_tile(position: tuple[int, int], grid: list[list[bool]]) -> bool:
+    return grid[position[0]][position[1]]
+
+
+def rotate_vector(vector: tuple[int, int]) -> tuple[int, int]:
+    if vector == (-1, 0):
+        return (0, 1)
+    elif vector == (0, 1):
+        return (1, 0)
+    elif vector == (1, 0):
+        return (0, -1)
+    elif vector == (0, -1):
+        return (-1, 0)
+    raise RuntimeError("Invalid rotation")
+
+
+if __name__ == "__main__":
+    print(globals()[sys.argv[1]]())