def dfs(start, end, obstacles=[], show_details=False):
# 1. create stack for DFS
# 2. visited contains all visited nodes
# 3. push start node to stack
# 4. pop a node from stack
stack = [(start, [start])]
visited = set()
mov = [(0, 1), (0, -1), (1, 0), (-1, 0)]
while stack:
(vertex, path) = stack.pop()
graph = list(
filter(lambda x: isValidCell(x, visited, obstacles),
[tuple(map(sum, zip(vertex, dir))) for dir in mov]))
if vertex not in visited:
if tools.cell_equal(vertex, end):
return path
visited.add(vertex)
for neighbor in graph:
stack.append((neighbor, path + [neighbor]))
if show_details:
canvas.draw_cell(vertex, canvas.COLOR.DARK_GREEN.value)
canvas.update()
return None
def run_game():
snake_coords = [(1, 2), (1, 1)]
apple = get_apple_coord(snake_coords)
score = 0
canvas.draw_bg()
canvas.draw_grid()
canvas.draw_cell_line(snake_coords, canvas.COLOR.DARK_GRAY.value,
canvas.COLOR.DARK_GREEN.value)
canvas.draw_cell(apple, canvas.COLOR.RED.value)
canvas.update()
while True:
n_coord = next_coord(snake_coords, apple)
if not n_coord:
print("Game Over! STUCK")
return
score += move(snake_coords, n_coord, apple, draw=True)
if not valid_coord(snake_coords[0], snake_coords[1:]):
print("Game Over!")
valid_coord(snake_coords[0], snake_coords[1:])
return
if len(snake_coords) == TOTAL:
print("Game KO!")
canvas.draw_grid()
return
if tools.cell_equal(n_coord, apple):
apple = get_apple_coord(snake_coords)
canvas.draw_cell(apple, canvas.COLOR.RED.value)
canvas.draw_grid()
def bfs(start, end, obstacles=[], show_details=False):
# 1. create empty queue for BFS
# 2. insert start position to queue
# 3. create visited dict containing position:neighbors
# 4. remove start from queue and then explore its neighbors
# 5. set graph equal to all the available neighbors
# 6. if neighbor has not been visited then add to visited{}. Push neighbor to queue.
# 7 if neighbor is equal to end return path
# 8. color in visited node
queue = [] #(1)
queue.append(start) #(2)
visited = {tools.cell_coordinates(start): None} #(3)
while queue:
node = queue.pop(0) #(4)
graph = tools.graph(node, visited, obstacles) #(5)
for neighbor in graph:
if tools.cell_coordinates(neighbor) in visited.keys(): #(6)
continue
visited[tools.cell_coordinates(neighbor)] = neighbor
queue.append(neighbor)
if tools.cell_equal(neighbor, end): #(7)
path = tools.path(visited, tools.cell_coordinates(neighbor))
return path[1:] + [end]
if show_details: #(8)
canvas.draw_cell(neighbor, canvas.COLOR.DARK_GREEN.value)
canvas.update()
return None
def cal(start, end, obstacles=[], show_details=False):
"""
使用DFS算法搜索路径
:param start: 起点
:param end: 终点
:param obstacles: 障碍
:param show_details: 是否显示细节
:return: 返回路径
"""
if tools.cell_equal(start, end):
return []
if tools.is_adjacent(start, end):
return [end]
queue = LifoQueue()
mark = {}
queue.put(Node(start))
while not queue.empty():
node = queue.get()
cell = node.cell
parent = node.parent
if tools.cal_cell_id(cell) in mark.keys():
# 已经遍历过了
continue
mark[tools.cal_cell_id(cell)] = parent
if show_details:
canvas.draw_cell(cell, canvas.COLOR.DARK_GREEN.value)
canvas.update()
if tools.cell_equal(cell, end):
path = tools.cal_path(mark, tools.cal_cell_id(end))
return path[1:] + [end]
adjs = tools.adj(cell, mark, obstacles)
for adj in adjs:
queue.put(Node(adj, cell))
return None
def cal(start, end, obstacles=[], show_details=False):
"""
使用A*算法搜索路径
:param start: 起点
:param end: 终点
:param obstacles: 障碍
:param show_details: 是否显示细节
:return: 返回路径
"""
if tools.cell_equal(start, end):
return []
if tools.is_adjacent(start, end):
return [end]
queue = PriorityQueue()
start_node = Node(start, 0, Node.cal_h(start, end))
queue.put(start_node, start_node.f)
mark = {tools.cal_cell_id(start): None}
while not queue.empty():
node = queue.get()
adjs = tools.adj(node.cell, mark, obstacles)
for adj in adjs:
if tools.cal_cell_id(adj) in mark.keys():
continue
mark[tools.cal_cell_id(adj)] = node.cell
adj_node = Node(adj, node.g + 1, Node.cal_h(adj, end))
queue.put(adj_node, adj_node.f)
if tools.cell_equal(adj, end):
path = tools.cal_path(mark, tools.cal_cell_id(adj))
return path[1:] + [end]
if show_details:
canvas.draw_cell(adj, canvas.COLOR.DARK_GREEN.value)
canvas.update()
return None
if __name__ == "__main__":
canvas.init("BFS")
canvas.draw_bg()
canvas.draw_grid()
start = (6, 5)
end = (12, 10)
obstacles = []
for x in range(4, 10):
obstacles.append((x, 3))
for x in range(4, 20):
obstacles.append((x, 12))
for y in range(2, 14):
obstacles.append((10, y))
for y in range(2, 16):
obstacles.append((17, y))
canvas.draw_cell(start, canvas.COLOR.GREEN.value)
canvas.draw_cell(end, canvas.COLOR.RED.value)
canvas.draw_cells(obstacles, canvas.COLOR.WHITE.value)
canvas.update()
input("Press <Enter> to start!")
path = bfs(start, end, obstacles, show_details=True)
canvas.draw_cell_line(path[:-1], canvas.COLOR.DARK_GRAY.value,
canvas.COLOR.RED.value)
canvas.update()
input("Press <Enter> to close!")
