27 lines
545 B
Plaintext
27 lines
545 B
Plaintext
|
#!/usr/bin/python3
|
||
|
|
|
||
|
|
from functools import lru_cache
|
||
|
|
|
||
|
|
adapters = []
|
||
|
|
with open("input") as fh:
|
||
|
|
for ln in fh:
|
||
|
|
adapters.append(int(ln))
|
||
|
|
|
||
|
|
adapters = sorted(adapters)
|
||
|
|
|
||
|
|
@lru_cache(maxsize=None)
|
||
|
|
def count(start, offset):
|
||
|
|
if offset == len(adapters) - 1:
|
||
|
|
return 1
|
||
|
|
n = 0
|
||
|
|
for i in range(offset, len(adapters)):
|
||
|
|
if adapters[i] - start < 1:
|
||
|
|
raise RuntimeError()
|
||
|
|
elif adapters[i] - start <= 3:
|
||
|
|
n += count(adapters[i], i+1)
|
||
|
|
else:
|
||
|
|
break
|
||
|
|
return n
|
||
|
|
|
||
|
|
print(count(0, 0))
|