def find_path(grid, algorithm='astar', heuristic=manhattan_distance):
'''
:param grid: initialized Grid object
:param algorithm: text string, one of the options in ALGORITHMS
:param heuristic: manhattan_distance or euclidean
:return: tuple of (1) list of nodes in the path from grid.start_node to grid.end_node
(2) list of remaining open nodes
(3) list of closed nodes
'''
use_heap_methods = (algorithm != 'bfs')
closed_nodes, open_nodes = list(), list()
push_node(open_nodes, grid.start_node)
while open_nodes:
current_node = pop_node(open_nodes, heap=use_heap_methods)
closed_nodes.append(current_node)
if current_node == grid.end_node:
return backtrack(current_node), open_nodes, closed_nodes
adjacent_nodes = grid.get_adjacent_nodes(current_node, allow_diagonal=False)
for adjacent_node in adjacent_nodes:
if adjacent_node in closed_nodes:
continue
new_g = current_node.g + adjacent_node.weight
if (adjacent_node not in open_nodes) or (adjacent_node.g and new_g < adjacent_node.g):
adjacent_node.g = new_g
adjacent_node.h = 0 if algorithm == 'dijkstra' else heuristic(adjacent_node, grid.end_node)
adjacent_node.parent = current_node
if adjacent_node not in open_nodes:
push_node(open_nodes, adjacent_node, heap=use_heap_methods)
def find_path(board, algorithm='astar', heuristic=manhattan_distance):
# board: initilize board object.
#algorithm: a text string (option in ALGORITHMS)
#heuristic: manhattan_distance
#return: 1, list of nodes in path from board.start_node to board.end_node
# 2, list of open nodes
# 3, list of closed nodes
use_heap_methods = (algorithm != 'bfs')
closed_nodes, open_nodes = list(), list()
push_node(open_nodes, board.start_node)
while open_nodes:
current_node = pop_node(open_nodes, heap=use_heap_methods)
closed_nodes.append(current_node)
if current_node == board.end_node:
return backtrack(current_node), open_nodes, closed_nodes
adjacent_nodes = board.get_adjacent_nodes(current_node, allow_diagonal=False)
for adjacent_node in adjacent_nodes:
if adjacent_node in closed_nodes:
continue
new_g = current_node.g + adjacent_node.weight
if (adjacent_node not in open_nodes) or (adjacent_node.g and new_g < adjacent_node.g):
adjacent_node.g = new_g
adjacent_node.h = 0 if algorithm == 'dijkstra' else heuristic(adjacent_node, board.end_node)
adjacent_node.parent = current_node
if adjacent_node not in open_nodes:
push_node(open_nodes, adjacent_node, heap=use_heap_methods)