adventOfCode/gridutil/coord.py
2023-12-23 13:44:38 +00:00

81 lines
No EOL
1.9 KiB
Python

from enum import Enum, auto
from collections import namedtuple
from numbers import Number
Coordinate = namedtuple("Coordinate", ["x", "y"])
Coordinate3 = namedtuple("Coordinate3", ["x", "y", "z"])
def add(a: Coordinate, b: Coordinate) -> Coordinate:
xa, ya = a
xb, yb = b
return Coordinate(xa + xb, ya + yb)
def sub(a: Coordinate, b: Coordinate) -> Coordinate:
xa, ya = a
xb, yb = b
return Coordinate(xa - xb, ya - yb)
def mult(a: Coordinate, b: Number) -> Coordinate:
x, y = a
return Coordinate(x * b, y * b)
def manhattan_dist(a: Coordinate, b: Coordinate) -> Number:
x, y = sub(b, a)
return abs(x) + abs(y)
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)