adventOfCode/gridutil/coord.py

83 lines
No EOL
2.1 KiB
Python

from enum import Enum, auto
from collections import namedtuple
from numbers import Number
from typing import TypeVar, Callable, Union
Coordinate = namedtuple("Coordinate", ["x", "y"])
Coordinate3 = namedtuple("Coordinate3", ["x", "y", "z"])
AnyCoordinate = Coordinate | Coordinate3
def _coordmap(a: AnyCoordinate, b: AnyCoordinate, fn: Callable) -> AnyCoordinate:
at = type(a)
return at(*map(fn, zip(a, b)))
def add(a: AnyCoordinate, b: AnyCoordinate) -> AnyCoordinate:
return _coordmap(a, b, lambda x: x[0] + x[1])
def sub(a: AnyCoordinate, b: AnyCoordinate) -> AnyCoordinate:
return _coordmap(a, b, lambda x: x[0] - x[1])
def mult(a: AnyCoordinate, b: Number) -> AnyCoordinate:
at = type(a)
return at(*map(lambda x: x * b, a))
def manhattan_dist(a: AnyCoordinate, b: AnyCoordinate) -> Number:
return sum(map(abs, sub(b, a)))
def area(x: list[Coordinate]) -> Number:
"""
Finds the area of a closed polygon.
https://en.wikipedia.org/wiki/Shoelace_formula
"""
acc = 0
for ((ax, ay), (bx, by)) in zip(x, x[1:] + [x[0]]):
acc += (ax * by) - (bx * ay)
return acc / 2
class Direction(Enum):
Up = auto()
Down = auto()
Left = auto()
Right = auto()
def delta(self) -> Coordinate:
match self:
case Direction.Up:
return Coordinate(0, -1)
case Direction.Down:
return Coordinate(0, 1)
case Direction.Left:
return Coordinate(-1, 0)
case Direction.Right:
return Coordinate(1, 0)
def opposite(self):
match self:
case Direction.Down:
return Direction.Up
case Direction.Up:
return Direction.Down
case Direction.Left:
return Direction.Right
case Direction.Right:
return Direction.Left
def __lt__(self, x):
return False
def __eq__(self, x):
if type(x) != Direction:
return False
return self.value == x.value
def __hash__(self):
return hash(self.value)