Add BFS algorithm
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54
survival/pathfinding.py
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54
survival/pathfinding.py
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from collections import deque as Queue
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def valid_neighbor(n, game_map, visited):
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if n[0] < 0 or n[1] < 0 or n[0] >= game_map.width or n[1] >= game_map.height:
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return False
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if visited[n[0]][n[1]]:
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return False
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if game_map.is_colliding(n):
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return False
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return True
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def breadth_first_search(game_map, start, target):
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visited = [[False for _ in range(game_map.width)] for _ in range(game_map.height)]
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q = Queue()
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came_from = dict()
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came_from[start] = (-1, -1)
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q.append(start)
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visited[start[0]][start[1]] = True
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while len(q) > 0:
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cell = q.popleft()
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if cell == target:
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break
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neighbors = [
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(cell[0] - 1, cell[1]),
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(cell[0], cell[1] + 1),
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(cell[0] + 1, cell[1]),
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(cell[0], cell[1] - 1),
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]
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for neighbor in neighbors:
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if valid_neighbor(neighbor, game_map, visited):
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q.append(neighbor)
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visited[neighbor[0]][neighbor[1]] = True
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came_from[neighbor] = cell
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path = list()
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current = target
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if came_from.get(start, None) is not None:
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path.append(start)
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return path
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while current != start:
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path.append(current)
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current = came_from[current]
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path.append(start)
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return path
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