递归走迷宫，练手。

23下午就写好的，可是测试几种不同的迷宫后，发现有个Bug，我以为算法有问题，今早才发现，原来是isDest函数里r和c都写成r了，拷贝out函数的语句再改写造成的悲剧。

#!/usr/bin/env python

# author: @nixzhu

# date: 2012.02.25

# description: Maze, use recursive.

#Door is (7, 7), as follow shows

# license: GPL

maze = [

[1,1,0,0,0,0,1,0],

[0,1,0,0,0,1,1,0],

[0,1,1,1,1,1,0,0],

[1,1,0,0,0,1,0,0],

[1,0,0,0,0,1,1,1],

[1,1,1,1,1,1,0,0],

[0,0,0,1,0,1,1,1],

[0,0,0,1,0,1,0,1]

]

maze_ = [

[0,0,0,0,0,0,0,0],

[0,0,0,0,0,0,0,0],

[0,0,0,0,0,0,0,0],

[0,0,0,0,0,0,0,0],

[0,0,0,0,0,0,0,0],

[0,0,0,0,0,0,0,0],

[0,0,0,0,0,0,0,0],

[0,0,0,0,0,0,0,0]

]

def showMaze(maze):

print '-----------------S'

for line in maze:

for l in line:

print l,

print ''

print '-----------------E'

def findDest(p={'r':0, 'c':0}):

if out(p):

#print '>> ++ out\t', p['r'], p['c']

return False

#print '>> -- out\t', p['r'], p['c']

if isWall(p):

return False

if wasVisited(p):

return False

visit(p)

if isDest(p):

print '('+str(p['r'])+', '+str(p['c'])+')'

maze_[p['r']][p['c']] = '#'

return True

else:

if findDest(p=left(p)):

print '('+str(p['r'])+', '+str(p['c'])+')'

maze_[p['r']][p['c']] = '#'

return True

if findDest(p=up(p)):

print '('+str(p['r'])+', '+str(p['c'])+')'

maze_[p['r']][p['c']] = '#'

return True

if findDest(p=right(p)):

print '('+str(p['r'])+', '+str(p['c'])+')'

maze_[p['r']][p['c']] = '#'

return True

if findDest(p=down(p)):

print '('+str(p['r'])+', '+str(p['c'])+')'

maze_[p['r']][p['c']] = '#'

return True

return False

def out(p={'r':0, 'c':0}):

if p['r'] < 0 or p['r'] > 7:

return True

if p['c'] < 0 or p['c'] > 7:

return True

return False

def isWall(p={'r':0, 'c':0}):

if maze[p['r']][p['c']] == 0:

return True

else:

return False

def wasVisited(p={'r':0, 'c':0}):

if maze[p['r']][p['c']] == 2:

return True

else:

return False

def isDest(p={'r':0, 'c':0}):

if p['r'] == 7 and p['c'] == 7:

return True

else:

return False

def visit(p={'r':0, 'c':0}):

maze[p['r']][p['c']] = 2

def left(p={'r':0, 'c':0}):

return {'r':p['r'], 'c':p['c']-1}

def right(p={'r':0, 'c':0}):

return {'r':p['r'], 'c':p['c']+1}

def up(p={'r':0, 'c':0}):

return {'r':p['r']-1, 'c':p['c']}

def down(p={'r':0, 'c':0}):

return {'r':p['r']+1, 'c':p['c']}

if __name__=='__main__':

showMaze(maze)

if not findDest(p={'r':0, 'c':0}):# Enter is (0, 0)

print "No, can't find destination"

else:

print "Yes, find destination"

showMaze(maze)

showMaze(maze_)

基本上没什么说的，主要是递归的思想。

迷宫的形式：0是墙，1是可走路径，2代表被走过的路。maze_用来显示路径，直观些。

如果我早些在最后调用findDest函数时加上条件判断来确认findDest的返回值，我应该能早些发现isDest里字符的错误。开始检查了几遍函数，居然都没发现，眼神不行了。今早还以为是visit函数的调用位置有问题，胡乱试是不会有结果的。