Files
python-aoc-2020/day10/part2.py
Sebastian Seedorf 06cae78503 Day 10 (inline prod)
2020-12-10 15:28:30 +01:00

37 lines
875 B
Python

import numpy as np
lines = sorted(int(x.strip()) for x in open("input.txt"))
lines.append(lines[-1]+3)
lines.insert(0, 0)
lines = np.array(lines)
diff = lines[1:] - lines[:-1]
one_count = 0
possibilities = 1
one_cache = {}
def count_one_possibilities(one_cnt: int):
if one_cnt not in one_cache:
if one_cnt <= 1:
one_cache[one_cnt] = 1
else:
one_cache[one_cnt] = sum(count_one_possibilities(less) for less in range(max(0, one_cnt - 3), one_cnt))
return one_cache[one_cnt]
# only 3 and 1 differences are available
# 3 has to be taken / calculate possibilities for 1 hops
for num in diff:
if num == 1:
one_count += 1
elif num == 3:
possibilities *= count_one_possibilities(one_count)
one_count = 0
print(possibilities) # 64793042714624
print(one_cache) # {0: 1, 1: 1, 2: 2, 3: 4, 4: 7}