迷宮問題之廣搜
#!/usr/bin/python3
# 檔名: StackClasq.py
# 作者: 巧若拙
# 日期: 2018年12月14日
from QueueClass import ListQueue,LinkQueue
OPEN, CLOSE, PASSED, ROAD = 0, 1, 2, -1 #分別表示該點通，不通，已走和屬於所選路徑
dirs = ((0, 1), (1, 0), (0, -1), (-1, 0)) #分別向東南西北走的行列座標變換情況
def mark(maze, pos):
maze[pos[0]][pos[1]] = PASSED
def passable(maze, pos): #判斷當前位置是否可通行
return maze[pos[0]][pos[1]] == OPEN
def print_path(start, end, path):#逆序輸出路徑
print(end, end = " ")
pos = path[end]
while path[pos] != pos:
print(pos, end = " ")
pos = path[pos]
print(start)
def extentSearch(maze, start, end): #用佇列實現廣度優先搜尋
if start == end:
print(start)
return True
q = LinkQueue()
mark(maze, start)
q.enqueue(start)
path = {start: start} #用字典記錄其前驅位置
while not q.is_empty():
pos = q.dequeue()
for i in range(4): #依次檢查四個方向
nextp = (pos[0]+dirs[i][0], pos[1]+dirs[i][1])
if passable(maze, nextp):
mark(maze, nextp)
q.enqueue(nextp)
path[nextp] = pos
if nextp == end:
print_path(start, end, path)
return True
return False
start = (1, 1)
end = (10, 12)
maze = [[1,1,1,1,1,1,1,1,1,1,1,1,1,1],
[1,0,0,0,1,1,0,0,0,1,0,0,0,1],
[1,0,1,0,0,0,0,1,0,1,0,1,0,1],
[1,0,1,0,1,1,0,1,0,1,0,1,0,1],
[1,0,1,0,0,0,0,0,0,1,1,1,0,1],
[1,0,1,1,1,1,1,1,1,1,0,0,0,1],
[1,0,1,0,0,0,0,0,0,0,0,1,0,1],
[1,0,0,0,1,1,1,0,1,0,1,1,0,1],
[1,0,1,0,1,0,1,0,1,0,1,0,0,1],
[1,0,1,0,1,0,1,0,1,1,1,1,0,1],
[1,0,1,0,0,0,0,0,0,0,0,0,0,1],
[1,1,1,1,1,1,1,1,1,1,1,1,1,1]]
print(extentSearch(maze, start, end))