#!/usr/bin/env python from typing import Iterator def is_valid_password(p: int) -> bool: digits = str(p) def has_adjacent_digit(): for (a, b) in zip(digits, digits[1:]): if a == b: return True return False def digits_never_decrease(): return all(a == b for a, b in zip(sorted(digits), digits)) return has_adjacent_digit() and digits_never_decrease() def compute_pass(begin: int, end: int) -> Iterator[int]: for p in range(begin, end + 1): if is_valid_password(p): yield p def main() -> None: begin = 264793 end = 803935 print(sum(1 for p in compute_pass(begin, end))) if __name__ == "__main__": main()