Day 04

aoc_2024/day_04/a.py

@@ -0,0 +1,93 @@
+from dataclasses import dataclass
+from functools import cached_property
+from typing import Sequence
+from aoc_2024.day_04.parser import Parser
+
+
+@dataclass
+class Day04PartASolver:
+    input: Sequence[Sequence[str]]
+
+    @property
+    def solution(self) -> int:
+        return sum(
+            [
+                self._vertical_count,
+                self._horizontal_count,
+                self._lr_diagonal_count,
+                self._rl_diagonal_count,
+            ]
+        )
+
+    @cached_property
+    def _forward(self) -> Sequence[str]:
+        return list("XMAS")
+
+    @cached_property
+    def _backward(self) -> Sequence[str]:
+        return self._forward[::-1]
+
+    @cached_property
+    def _height(self) -> int:
+        return len(self.input)
+
+    @cached_property
+    def _width(self) -> int:
+        return len(self.input[0])
+
+    @cached_property
+    def _vertical_count(self) -> int:
+        output = 0
+        for y in range(self._height - 3):
+            for x in range(self._width):
+                vals = [self.input[y + i][x] for i in range(4)]
+                if vals in (self._forward, self._backward):
+                    output += 1
+        return output
+
+    @cached_property
+    def _horizontal_count(self) -> int:
+        output = 0
+        for y in range(self._height):
+            for x in range(self._width - 3):
+                vals = [self.input[y][x + i] for i in range(4)]
+                if vals in (self._forward, self._backward):
+                    output += 1
+        return output
+
+    @cached_property
+    def _lr_diagonal_count(self) -> int:
+        output = 0
+        for y in range(self._height - 3):
+            for x in range(self._width - 3):
+                vals = [self.input[y + i][x + i] for i in range(4)]
+                if vals in (self._forward, self._backward):
+                    output += 1
+        return output
+
+    @cached_property
+    def _rl_diagonal_count(self) -> int:
+        output = 0
+        for y in range(self._height - 3):
+            for x in range(self._width - 3):
+                vals = [self.input[y + 3 - i][x + i] for i in range(4)]
+                if vals in (self._forward, self._backward):
+                    output += 1
+        return output
+
+
+def solve(input: str) -> int:
+    data = Parser.parse(input)
+    solver = Day04PartASolver(data)
+
+    return solver.solution
+
+
+def get_solution() -> int:
+    with open("aoc_2024/day_04/input.txt", "r") as f:
+        input = f.read()
+    return solve(input)
+
+
+if __name__ == "__main__":
+    print(get_solution())

aoc_2024/day_04/b.py

@@ -0,0 +1,54 @@
+from dataclasses import dataclass
+from functools import cached_property
+from typing import Sequence
+from aoc_2024.day_04.parser import Parser
+
+
+@dataclass
+class Day04PartBSolver:
+    input: Sequence[Sequence[str]]
+
+    @property
+    def solution(self) -> int:
+        output = 0
+        target = (self._forward, self._backward)
+        for y in range(self._height - 2):
+            for x in range(self._width - 2):
+                lr_vals = [self.input[y + i][x + i] for i in range(3)]
+                rl_vals = [self.input[y + 2 - i][x + i] for i in range(3)]
+                if lr_vals in target and rl_vals in target:
+                    output += 1
+        return output
+
+    @cached_property
+    def _forward(self) -> Sequence[str]:
+        return list("MAS")
+
+    @cached_property
+    def _backward(self) -> Sequence[str]:
+        return self._forward[::-1]
+
+    @cached_property
+    def _height(self) -> int:
+        return len(self.input)
+
+    @cached_property
+    def _width(self) -> int:
+        return len(self.input[0])
+
+
+def solve(input: str) -> int:
+    data = Parser.parse(input)
+    solver = Day04PartBSolver(data)
+
+    return solver.solution
+
+
+def get_solution() -> int:
+    with open("aoc_2024/day_04/input.txt", "r") as f:
+        input = f.read()
+    return solve(input)
+
+
+if __name__ == "__main__":
+    print(get_solution())

aoc_2024/day_04/parser.py

@@ -0,0 +1,8 @@
+from typing import Sequence
+
+
+class Parser:
+    @staticmethod
+    def parse(input: str) -> Sequence[Sequence[str]]:
+        lines = input.strip().splitlines()
+        return [list(line) for line in lines]

tests/test_day_04/test_a.py

@@ -0,0 +1,10 @@
+from aoc_2024.day_04.a import get_solution, solve
+from aoc_2024.day_04.from_prompt import SAMPLE_DATA, SAMPLE_SOLUTION_A, SOLUTION_A
+
+
+def test_solve():
+    assert solve(SAMPLE_DATA) == SAMPLE_SOLUTION_A
+
+
+def test_my_solution():
+    assert get_solution() == SOLUTION_A

tests/test_day_04/test_b.py

@@ -0,0 +1,13 @@
+import pytest
+
+from aoc_2024.day_04.b import get_solution, solve
+from aoc_2024.day_04.from_prompt import SAMPLE_DATA, SAMPLE_SOLUTION_B, SOLUTION_B
+
+
+def test_solve():
+    assert solve(SAMPLE_DATA) == SAMPLE_SOLUTION_B
+
+
+@pytest.mark.skip
+def test_my_solution():
+    assert get_solution() == SOLUTION_B