day 02

src/aoc/aoc2024/day_02.py

@@ -0,0 +1,43 @@
+from collections.abc import Iterable
+from itertools import pairwise
+from typing import TypeAlias
+
+from src.aoc.aoc2024 import YEAR, get_day
+from src.aoc.aoc_helper import Aoc
+
+Nums: TypeAlias = Iterable[int]
+
+
+Nums: TypeAlias = Iterable[int]
+
+
+def safe(nums: Nums, /) -> bool:
+    match [b - a for a, b in pairwise(nums)]:
+        case [*diffs] if all(d in {1, 2, 3} for d in diffs) or all(
+            d in {-1, -2, -3} for d in diffs
+        ):
+            return True
+        case _:
+            return False
+
+
+def part_a(txt: str) -> int:
+    return sum(safe(map(int, nums)) for nums in map(str.split, txt.splitlines()))
+
+
+def part_b(txt: str) -> int:
+    return sum(
+        safe(nums := list(map(int, line.split())))
+        or any(safe(nums[:i] + nums[i + 1 :]) for i in range(len(nums)))
+        for line in txt.splitlines()
+    )
+
+
+def main(txt: str) -> None:
+    print("part_a: ", part_a(txt))
+    print("part_b: ", part_b(txt))
+
+
+if __name__ == "__main__":
+    aoc = Aoc(day=get_day(), years=YEAR)
+    aoc.run(main, submit=True, part="both", readme_update=True)

src/aoc/aoc2024/readme.md

@@ -3,7 +3,7 @@
 | Day | Problem | Part A | Part B | Complete |
 |-----|---------|---------|---------|----------|
 | 01 | [Historian Hysteria](https://adventofcode.com/2024/day/1) | :heavy_check_mark: | :heavy_check_mark: | :heavy_check_mark: |
-| 02 | [?](https://adventofcode.com/2024/day/2) | :x: | :x: | :x: |
+| 02 | [Red-Nosed Reports](https://adventofcode.com/2024/day/2) | :heavy_check_mark: | :heavy_check_mark: | :heavy_check_mark: |
 | 03 | [?](https://adventofcode.com/2024/day/3) | :x: | :x: | :x: |
 | 04 | [?](https://adventofcode.com/2024/day/4) | :x: | :x: | :x: |
 | 05 | [?](https://adventofcode.com/2024/day/5) | :x: | :x: | :x: |

tests/aoc2024/2024_day_02_test.py

@@ -0,0 +1,20 @@
+import pytest
+
+from src.aoc.aoc2024 import day_02 as d
+
+TEST_INPUT = """
+7 6 4 2 1
+1 2 7 8 9
+9 7 6 2 1
+1 3 2 4 5
+8 6 4 4 1
+1 3 6 7 9
+""".strip()
+
+
+def test_a() -> None:
+    assert d.part_a(TEST_INPUT) == 2
+
+
+def test_b() -> None:
+    assert d.part_b(TEST_INPUT) == 4