2026-rff_mp/BolonkinNM/strategies/dijkstra_strategy.py

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2026-05-24 16:39:37 +00:00
import heapq
from strategies.pathfinding_strategy import PathFindingStrategy
class DijkstraStrategy(PathFindingStrategy):
name = "Dijkstra"
def findPath(self, maze, start, exitCell):
self.visitedCount = 0
if start is None or exitCell is None:
return []
pq = [(0, start.x, start.y, start)]
dist = {(start.x, start.y): 0}
parent = {}
closed = set()
while pq:
current_cost, _, _, current = heapq.heappop(pq)
pos = (current.x, current.y)
if pos in closed:
continue
closed.add(pos)
self.visitedCount += 1
if current.x == exitCell.x and current.y == exitCell.y:
return self._restore_path(parent, start, exitCell)
for neighbor in maze.getNeighbors(current):
npos = (neighbor.x, neighbor.y)
step_cost = getattr(neighbor, "weight", 1)
new_cost = current_cost + step_cost
if new_cost < dist.get(npos, float("inf")):
dist[npos] = new_cost
parent[npos] = current
heapq.heappush(pq, (new_cost, neighbor.x, neighbor.y, neighbor))
return []