109 lines
2.7 KiB
Python
109 lines
2.7 KiB
Python
|
#!/usr/bin/env python
|
||
|
|
|
||
|
|
import enum
|
||
|
|
import functools
|
||
|
|
import itertools
|
||
|
|
import sys
|
||
|
|
from typing import Literal, NamedTuple
|
||
|
|
|
||
|
|
|
||
|
|
class Point(NamedTuple):
|
||
|
|
x: int
|
||
|
|
y: int
|
||
|
|
|
||
|
|
|
||
|
|
class Direction(enum.StrEnum):
|
||
|
|
UP = "^"
|
||
|
|
DOWN = "v"
|
||
|
|
LEFT = "<"
|
||
|
|
RIGHT = ">"
|
||
|
|
|
||
|
|
|
||
|
|
Instruction = Direction | Literal["A"]
|
||
|
|
|
||
|
|
PAD = {
|
||
|
|
"7": Point(-3, -2),
|
||
|
|
"8": Point(-3, -1),
|
||
|
|
"9": Point(-3, 0),
|
||
|
|
"4": Point(-2, -2),
|
||
|
|
"5": Point(-2, -1),
|
||
|
|
"6": Point(-2, 0),
|
||
|
|
"1": Point(-1, -2),
|
||
|
|
"2": Point(-1, -1),
|
||
|
|
"3": Point(-1, 0),
|
||
|
|
"0": Point(0, -1),
|
||
|
|
"A": Point(0, 0),
|
||
|
|
}
|
||
|
|
|
||
|
|
ARROWS = {
|
||
|
|
"^": Point(0, -1),
|
||
|
|
"A": Point(0, 0),
|
||
|
|
"<": Point(1, -2),
|
||
|
|
"v": Point(1, -1),
|
||
|
|
">": Point(1, 0),
|
||
|
|
}
|
||
|
|
|
||
|
|
# Needs to be hash-able
|
||
|
|
InstructionList = tuple[Instruction, ...]
|
||
|
|
|
||
|
|
|
||
|
|
def solve(input: str) -> int:
|
||
|
|
def button_paths(
|
||
|
|
start_button: str,
|
||
|
|
end_button: str,
|
||
|
|
buttons: dict[str, Point],
|
||
|
|
) -> set[InstructionList]:
|
||
|
|
start, end = buttons[start_button], buttons[end_button]
|
||
|
|
sequences: set[InstructionList] = set()
|
||
|
|
|
||
|
|
dx, dy = (end.x - start.x), (end.y - start.y)
|
||
|
|
|
||
|
|
a_button: list[Instruction] = ["A"] # Work around MyPy limitation
|
||
|
|
move_x = [Direction.UP if dx < 0 else Direction.DOWN] * abs(dx)
|
||
|
|
move_y = [Direction.LEFT if dy < 0 else Direction.RIGHT] * abs(dy)
|
||
|
|
|
||
|
|
# Avoid moving over the gap
|
||
|
|
if Point(end.x, start.y) in buttons.values():
|
||
|
|
sequences.add(tuple(a_button + move_x + move_y + a_button))
|
||
|
|
if Point(start.x, end.y) in buttons.values():
|
||
|
|
sequences.add(tuple(a_button + move_y + move_x + a_button))
|
||
|
|
|
||
|
|
return sequences
|
||
|
|
|
||
|
|
@functools.cache
|
||
|
|
def path_cost(path: InstructionList, depth: int) -> int:
|
||
|
|
# Have we reached the actual keypad robot
|
||
|
|
if depth == 0:
|
||
|
|
# We start on 'A' so don't count it
|
||
|
|
return len(path) - 1
|
||
|
|
# Otherwise, intermediate robot must use arrow pad
|
||
|
|
cost = sum(
|
||
|
|
min(path_cost(path, depth - 1) for path in button_paths(start, end, ARROWS))
|
||
|
|
for start, end in itertools.pairwise(path)
|
||
|
|
)
|
||
|
|
return cost
|
||
|
|
|
||
|
|
def code_cost(code: str, depth: int) -> int:
|
||
|
|
# We start on 'A'
|
||
|
|
code = "A" + code
|
||
|
|
cost = sum(
|
||
|
|
min(path_cost(path, depth) for path in button_paths(start, end, PAD))
|
||
|
|
for start, end in itertools.pairwise(code)
|
||
|
|
)
|
||
|
|
return cost
|
||
|
|
|
||
|
|
def complexity(code: str, seq_len: int) -> int:
|
||
|
|
return int(code.replace("A", "")) * seq_len
|
||
|
|
|
||
|
|
codes = input.splitlines()
|
||
|
|
return sum(complexity(code, code_cost(code, 25)) for code in codes)
|
||
|
|
|
||
|
|
|
||
|
|
def main() -> None:
|
||
|
|
input = sys.stdin.read()
|
||
|
|
print(solve(input))
|
||
|
|
|
||
|
|
|
||
|
|
if __name__ == "__main__":
|
||
|
|
main()
|