advent-of-code/2022/d06/ex1/ex1.py

37 lines
765 B
Python
Executable file

#!/usr/bin/env python
import collections
import itertools
import sys
from collections.abc import Iterable
from typing import TypeVar
T = TypeVar("T")
def sliding_window(iterable: Iterable[T], n: int) -> Iterable[tuple[T, ...]]:
it = iter(iterable)
window = collections.deque(itertools.islice(it, n), maxlen=n)
if len(window) == n:
yield tuple(window)
for x in it:
window.append(x)
yield tuple(window)
def solve(input: str) -> int:
SIZE = 4
for i, tup in enumerate(sliding_window(input, SIZE), start=SIZE):
if len(set(tup)) == SIZE:
return i
assert False
def main() -> None:
input = sys.stdin.read().replace("\n", "")
print(solve(input))
if __name__ == "__main__":
main()