public/aoc2022
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

day12 - some slight optimizations

Browse Source
This commit is contained in:
Stefan Harmuth 2022-12-12 08:12:01 +01:00
parent f1109d71a7
commit a11cefa083
1 changed files with 12 additions and 14 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

26
day12.py
View File

@ -1,16 +1,16 @@
from heapq import heappush, heappop
from tools.aoc import AOCDay
from tools.coordinate import Coordinate
from tools.coordinate import Coordinate, DistanceAlgorithm
from tools.grid import Grid
from typing import Any
def get_dijkstra_path(height_map: Grid, start: Coordinate, end: Coordinate) -> list | None:
def get_dijkstra_path(height_map: Grid, start: Coordinate, end: Coordinate) -> int | None:
f_costs = []
openNodes = {}
closedNodes = {}
openNodes[start] = (0, start.getDistanceTo(end), None)
openNodes[start] = (0, start.getDistanceTo(end, algorithm=DistanceAlgorithm.MANHATTAN), None)
heappush(f_costs, (0, start))
while f_costs:
@ -28,25 +28,23 @@ def get_dijkstra_path(height_map: Grid, start: Coordinate, end: Coordinate) -> l
if neighbour in closedNodes or height_map.get(neighbour) - 1 > height_map.get(currentCoord):
continue
neighbourDist = 1
targetDist = neighbour.getDistanceTo(end)
f_cost = targetDist + neighbourDist + currentNode[1]
targetDist = neighbour.getDistanceTo(end, algorithm=DistanceAlgorithm.MANHATTAN)
f_cost = targetDist + 1 + currentNode[1]
if neighbour not in openNodes or f_cost < openNodes[neighbour][0]:
openNodes[neighbour] = (f_cost, currentNode[1] + neighbourDist, currentCoord)
openNodes[neighbour] = (f_cost, currentNode[1] + 1, currentCoord)
heappush(f_costs, (f_cost, neighbour))
if end not in closedNodes:
return None
else:
steps = 0
currentNode = closedNodes[end]
pathCoords = [end]
while currentNode[2]:
pathCoords.append(currentNode[2])
steps += 1
currentNode = closedNodes[currentNode[2]]
return pathCoords
return steps
class Day(AOCDay):
@ -79,7 +77,7 @@ class Day(AOCDay):
return grid, start, end
def part1(self) -> Any:
return len(get_dijkstra_path(*self.get_map())) - 1
return get_dijkstra_path(*self.get_map())
def part2(self) -> Any:
min_steps = float("inf")
@ -87,8 +85,8 @@ class Day(AOCDay):
for c in height_map.getActiveCells():
if height_map.get(c) == 0:
steps_from_here = get_dijkstra_path(height_map, c, end)
if steps_from_here is not None and len(steps_from_here) < min_steps:
min_steps = len(steps_from_here)
if steps_from_here is not None and steps_from_here + 1 < min_steps:
min_steps = steps_from_here + 1
return min_steps - 1