50 lines
1.4 KiB
Python
50 lines
1.4 KiB
Python
|
import re
|
||
|
|
|
||
|
|
from solutions import BaseSolution
|
||
|
|
|
||
|
|
|
||
|
|
class Solution(BaseSolution):
|
||
|
|
input_file = "07.txt"
|
||
|
|
|
||
|
|
def __str__(self):
|
||
|
|
return "Day 7: Handy Haversacks"
|
||
|
|
|
||
|
|
def parse_input(self, data):
|
||
|
|
rules = []
|
||
|
|
for rule in data.splitlines():
|
||
|
|
prnt, *children = re.findall(r"((\d+ )?(\S+ \S+)) bags?", rule.strip())
|
||
|
|
parent_color = prnt[0]
|
||
|
|
try:
|
||
|
|
rules.append(
|
||
|
|
(parent_color, [(n, int(q.strip())) for _, q, n in children])
|
||
|
|
)
|
||
|
|
except ValueError:
|
||
|
|
# "no other" case, return empty children list
|
||
|
|
rules.append((parent_color, []))
|
||
|
|
return rules
|
||
|
|
|
||
|
|
def solve(self, bags):
|
||
|
|
seen = set()
|
||
|
|
self.child_of(bags, "shiny gold", seen)
|
||
|
|
return len(seen)
|
||
|
|
|
||
|
|
def solve_again(self, bags):
|
||
|
|
return self.weight(dict(bags), "shiny gold")
|
||
|
|
|
||
|
|
def child_of(self, bags, child, seen):
|
||
|
|
parents = [bag[0] for bag in bags if child in str(bag[1])]
|
||
|
|
seen.update(parents)
|
||
|
|
for parent in parents:
|
||
|
|
self.child_of(bags, parent, seen)
|
||
|
|
|
||
|
|
def weight(self, rules, bag):
|
||
|
|
children = rules[bag]
|
||
|
|
child_weight = sum(q for _, q in children)
|
||
|
|
child_weight += sum(q * self.weight(rules, name) for name, q in children)
|
||
|
|
return child_weight
|
||
|
|
|
||
|
|
|
||
|
|
if __name__ == "__main__":
|
||
|
|
solution = Solution()
|
||
|
|
solution.show_results()
|