2021/d21/ex1/ex1.py

@@ -1,78 +0,0 @@
-#!/usr/bin/env python
-
-import itertools
-import sys
-from typing import Iterable, Iterator, List, NamedTuple, Tuple, TypeVar
-
-T = TypeVar("T")
-
-
-def grouper(iterable: Iterable[T], n: int) -> Iterator[Tuple[T, ...]]:
-    args = [iter(iterable)] * n
-    return itertools.zip_longest(*args)
-
-
-def take(n: int, iterable: Iterable[T]) -> List[T]:
-    return list(itertools.islice(iterable, n))
-
-
-class PlayerStats(NamedTuple):
-    position: int
-    score: int
-
-
-class GameState(NamedTuple):
-    p1: PlayerStats
-    p2: PlayerStats
-    total_rolls: int
-
-
-WINNING_SCORE = 1000
-
-
-def solve(input: List[str]) -> int:
-    def parse() -> Tuple[int, int]:
-        p1, p2 = input[0].split(" ")[-1], input[1].split(" ")[-1]
-        return int(p1), int(p2)
-
-    def deterministic_die() -> Iterator[int]:
-        return itertools.cycle(range(1, 100 + 1))
-
-    def do_turn(stats: PlayerStats, rolls: Iterator[int]) -> PlayerStats:
-        position, score = stats
-        roll = sum(take(3, rolls))
-        position = ((position - 1 + roll) % 10) + 1
-        score += position
-        return PlayerStats(position, score)
-
-    def play_to_end(intial_state: GameState) -> GameState:
-        p1, p2, total_rolls = intial_state
-        die_rolls = deterministic_die()
-
-        while True:
-            p1 = do_turn(p1, die_rolls)
-            total_rolls += 3
-            if p1.score >= WINNING_SCORE:
-                break
-            p2 = do_turn(p2, die_rolls)
-            total_rolls += 3
-            if p2.score >= WINNING_SCORE:
-                break
-
-        return GameState(p1, p2, total_rolls)
-
-    position1, position2 = parse()
-    p1, p2, total_rolls = play_to_end(
-        GameState(PlayerStats(position1, 0), PlayerStats(position2, 0), 0)
-    )
-    # The loser *must* have the lowest score
-    return min(p1.score, p2.score) * total_rolls
-
-
-def main() -> None:
-    input = [line.strip() for line in sys.stdin.readlines()]
-    print(solve(input))
-
-
-if __name__ == "__main__":
-    main()

2021/d21/ex1/input

@@ -1,2 +0,0 @@
-Player 1 starting position: 8
-Player 2 starting position: 5

2021/d21/ex2/ex2.py

@@ -1,79 +0,0 @@
-#!/usr/bin/env python
-
-import functools
-import itertools
-import sys
-from typing import Iterable, Iterator, List, NamedTuple, Tuple, TypeVar
-
-T = TypeVar("T")
-
-
-def grouper(iterable: Iterable[T], n: int) -> Iterator[Tuple[T, ...]]:
-    args = [iter(iterable)] * n
-    return itertools.zip_longest(*args)
-
-
-def take(n: int, iterable: Iterable[T]) -> List[T]:
-    return list(itertools.islice(iterable, n))
-
-
-class PlayerStats(NamedTuple):
-    position: int
-    score: int
-
-
-ROLL_TO_UNIVERSES = {
-    3: 1,
-    4: 3,
-    5: 6,
-    6: 7,
-    7: 6,
-    8: 3,
-    9: 1,
-}
-
-WINNING_SCORE = 21
-
-
-def solve(input: List[str]) -> int:
-    def parse() -> Tuple[int, int]:
-        p1, p2 = input[0].split(" ")[-1], input[1].split(" ")[-1]
-        return int(p1), int(p2)
-
-    def do_turn(stats: PlayerStats, roll: int) -> PlayerStats:
-        position, score = stats
-        position = ((position - 1 + roll) % 10) + 1
-        score += position
-        return PlayerStats(position, score)
-
-    @functools.cache
-    def play_universes(p1: PlayerStats, p2: PlayerStats) -> Tuple[int, int]:
-        p1_wins, p2_wins = 0, 0
-
-        # Only 9 different outcomes from a 3d3 roll, with differing probabilities
-        for roll, roll_probability in ROLL_TO_UNIVERSES.items():
-            new_p1 = do_turn(p1, roll)
-            if new_p1.score >= WINNING_SCORE:
-                # Account for differing number of split universes when counting a win
-                p1_wins += roll_probability
-                continue
-
-            # Exchange p1 and p2 roles, count their wins, and account for number of splits
-            new_p2_wins, new_p1_wins = play_universes(p2, new_p1)
-            p1_wins += new_p1_wins * roll_probability
-            p2_wins += new_p2_wins * roll_probability
-
-        return p1_wins, p2_wins
-
-    p1, p2 = parse()
-    p1_wins, p2_wins = play_universes(PlayerStats(p1, 0), PlayerStats(p2, 0))
-    return max(p1_wins, p2_wins)
-
-
-def main() -> None:
-    input = [line.strip() for line in sys.stdin.readlines()]
-    print(solve(input))
-
-
-if __name__ == "__main__":
-    main()

2021/d21/ex2/input

@@ -1,2 +0,0 @@
-Player 1 starting position: 8
-Player 2 starting position: 5