Implement 2024 day 19

2024/src/aoc/days/day19.py

@@ -0,0 +1,37 @@
+import functools
+
+from . import CombinedRunner
+
+
+def parse_input(data: str) -> tuple[tuple[str, ...], list[str]]:
+    patterns, designs = data.strip().split("\n\n")
+
+    return tuple(patterns.split(", ")), designs.split("\n")
+
+
+@functools.cache
+def is_possible(design: str, patterns: tuple[str, ...]) -> bool:
+    if not design:
+        return 1
+
+    return sum(
+        is_possible(design[len(pat) :], patterns)
+        for pat in patterns
+        if design.startswith(pat)
+    )
+
+
+class DayRunner(CombinedRunner):
+    @classmethod
+    def run_both(cls, input: str) -> int:
+        patterns, designs = parse_input(input)
+
+        possible = 0
+        ways = 0
+
+        for design in designs:
+            if (solve := is_possible(design, patterns)) > 0:
+                possible += 1
+                ways += solve
+
+        return possible, ways