Poor man's trie

This commit is contained in:
2024-12-19 22:35:55 +01:00
parent 891a5ea50c
commit dd07090056

View File

@@ -1,12 +1,13 @@
import collections
import functools
from . import CombinedRunner
def parse_input(data: str) -> tuple[tuple[str, ...], list[str]]:
def parse_input(data: str) -> tuple[list[str], list[str]]:
patterns, designs = data.strip().split("\n\n")
return tuple(patterns.split(", ")), designs.split("\n")
return patterns.split(", "), designs.split("\n")
class DayRunner(CombinedRunner):
@@ -14,6 +15,10 @@ class DayRunner(CombinedRunner):
def run_both(cls, input: str) -> int:
patterns, designs = parse_input(input)
by_prefix = collections.defaultdict(list)
for prefix in patterns:
by_prefix[prefix[0]].append(prefix)
possible = 0
ways = 0
@@ -21,11 +26,11 @@ class DayRunner(CombinedRunner):
def is_possible(design: str) -> bool:
if not design:
return 1
else:
return sum(
is_possible(design[len(pat) :])
for pat in patterns
if design.startswith(pat)
is_possible(design[len(prefix) :])
for prefix in by_prefix[design[0]]
if design.startswith(prefix)
)
for design in designs: