Day 2: Cube Conundrum

py/aoc2023/day2.py

@@ -0,0 +1,54 @@
+"""
+Day 2: Cube Conundrum
+"""
+
+import re
+from collections import defaultdict
+from math import prod
+
+SAMPLE_INPUT = """
+Game 1: 3 blue, 4 red; 1 red, 2 green, 6 blue; 2 green
+Game 2: 1 blue, 2 green; 3 green, 4 blue, 1 red; 1 green, 1 blue
+Game 3: 8 green, 6 blue, 20 red; 5 blue, 4 red, 13 green; 5 green, 1 red
+Game 4: 1 green, 3 red, 6 blue; 3 green, 6 red; 3 green, 15 blue, 14 red
+Game 5: 6 red, 1 blue, 3 green; 2 blue, 1 red, 2 green
+"""
+
+GAME_RE = re.compile(r"Game (\d+): ")
+CUBE_RE = re.compile(r"(\d+) (\w+)")
+
+
+def _parse(data):
+    for line in data.splitlines():
+        if not (match := GAME_RE.match(line)):
+            continue
+        game_id = int(match.group(1))
+        cubes = defaultdict(int)
+        for match in CUBE_RE.finditer(line):
+            count = int(match.group(1))
+            color = match.group(2)
+            cubes[color] = max(cubes[color], count)
+        yield game_id, cubes
+
+
+def part1(data):
+    """
+    >>> part1(SAMPLE_INPUT)
+    8
+    """
+    acc = 0
+    for game_id, cubes in _parse(data):
+        if cubes["red"] <= 12 and cubes["green"] <= 13 and cubes["blue"] <= 14:
+            acc += game_id
+    return acc
+
+
+def part2(data):
+    """
+    >>> part2(SAMPLE_INPUT)
+    2286
+    """
+    return sum(prod(cubes.values()) for _, cubes in _parse(data))
+
+
+parts = (part1, part2)

py/pyproject.toml

@@ -23,6 +23,7 @@ aoc2023 = "aoc2023.main:main"
 
 [tool.poetry.plugins."aoc2023.days"]
 day1 = "aoc2023.day1:parts"
+day2 = "aoc2023.day2:parts"
 
 [tool.black]
 target_version = ["py312"]