aoc2021/day09.py
2021-12-09 06:33:46 +01:00

51 lines
1.5 KiB
Python

from tools.aoc import AOCDay
from tools.coordinate import Coordinate
from tools.grid import Grid
from typing import Any, List
def getCaveMapFromInput(puzzle_input: List[str]) -> Grid:
caveMap = Grid(99)
for y, s in enumerate(puzzle_input):
for x, v in enumerate(s):
caveMap.set(Coordinate(x, y), int(v))
return caveMap
def getLowPoints(caveMap: Grid) -> List[Coordinate]:
lowPoints = []
for point in caveMap.getActiveCells():
if not sum((caveMap.get(t) <= caveMap.get(point)) for t in point.getNeighbours(includeDiagonal=False)):
lowPoints.append(point)
return lowPoints
def getBasin(caveMap: Grid, start: Coordinate, visited: set) -> set:
for n in start.getNeighbours(includeDiagonal=False):
if n in visited:
continue
if caveMap.get(n) < 9:
visited.add(n)
visited = set.union(visited, getBasin(caveMap, n, visited))
return visited
class Day(AOCDay):
test_solutions_p1 = [15]
test_solutions_p2 = [1134]
def part1(self) -> Any:
caveMap = getCaveMapFromInput(self.getInput())
return sum(caveMap.get(x) + 1 for x in getLowPoints(caveMap))
def part2(self) -> Any:
caveMap = getCaveMapFromInput(self.getInput())
lowPoints = getLowPoints(caveMap)
basins = list(sorted([getBasin(caveMap, point, set()) for point in lowPoints], key=lambda l: len(l)))
return len(basins[-1]) * len(basins[-2]) * len(basins[-3])