# -*- coding: utf-8 -*-
# @Time : 2017/8/10 上午9:42
# @Author : Qi MO
# @File : BFS.py
# @Software: PyCharm Community Edition
 
level_file_path = '../数据/level_file.txt'
 
class GameShortest:
 def __init__(self,line, col=10):
  """
  给一个图，长度为100的字符串表示。
  0空地 1墙 2箱子起始位置 3箱子终点位置 4人的起始位置
  :param line: 地图，用字符串表示。如代码最后的每一行表示每一关的地图。
  :param col: 地图的长宽，由于设定为10*10，默认为10
  """
 
  self.line = line
  # sta和en 表示开始的状态，结束的状态
  # sta只有2,4,0 2表示箱子开始位置,4表示人的位置,0表示其他。
  # en只有1,3,0 1表示墙,3表示箱子结束位置,0表示其他。
  # 现在只需要把sta状态中的2位置移动到en的3的位置即满足条件
  self.sta = ''
  self.en = ''
  self.col = col
  # px, py表示4的位置
  self.px,self.py = -1,-1
  # paths记录最短路径（可能有多条）
  self.paths = []
  # len记录最短路径长度 如
  self.len = -1
 
  self.pre()
  self.BFS()
  print(self.paths)
 
 def pre(self):
  """
  1.获得sta开始状态和en结束状态
  2.获得人的起始位置px,py
  代码最后的第一关的地图可视化为
  1111111111
  1111111111
  1110001111
  1110221111
  1114201111
  1111100111
  1111300111
  1113300111
  1111111111
  1111111111
  :return:
  """
  mp = []
  for pos in range(0, 100, 10):
   mp.append(self.line[pos:pos + 10])
  # print(self.line)
  # for x in mp:
  #  print(x)
 
  for pos, enum in enumerate(self.line):
   cx, cy = pos // 10, pos % 10
   if enum == '4':
    self.px, self.py = cx, cy
  # 现在只需要把sta开始的状态中的2位置移动到en的3的位置即满足条件
  staDic = {'0': '0', '1': '0', '2': '2', '3': '0', '4': '4'}
  enDic = {'0': '0', '1': '1', '2': '0', '3': '3', '4': '0'}
  for x in self.line:
   self.sta += staDic[x]
   self.en += enDic[x]
  # print(self.sta)
  # print(self.en)
 
 def is_ok(self,sta):
  """
  sta状态中的2位置移动到en的3的位置。
  :param sta:
  :return:
  """
  for s,e in zip(sta,self.en):
   if e == '3' and s != '2':
    return False
  return True
 
 def BFS(self):
  """
  BFS获得最短路径保存到paths中
  :return:
  """
  # 4个方向，小写代表只是人移动，大写表示人推着箱子一起移动
  dirs = [[-1,0,'u','U'],[1,0,'d','D'],[0,1,'r','R'],[0,-1,'l','L']]
  # 把开始的状态进入队列(list模拟)，状态包括字符串表示的当前状态、当前的路径、当前人的位置
  states = [[self.sta,'',self.px,self.py]]
  # 访问数组(dict模拟)，访问过的状态（字符串）不再访问
  visi = {}
  visi[self.sta] = 1
 
  s_len = 1000
  while len(states)>0:
   sta, path, px, py = states[0]
   # 4状态的位置
   ppos = px*self.col + py
   states = states[1:]
   if len(path)>s_len:
    break
   # 保存最短路径到paths中
   if self.is_ok(sta):
    if self.len == -1 or len(path) == self.len:
     self.paths.append(path)
     self.len = len(path)
    continue
 
   for dir in dirs:
    cx, cy = px + dir[0], py + dir[1]
    # 4挨着的状态的位置
    pos = cx*self.col+cy
    nx, ny = px + 2*dir[0], py + 2*dir[1]
    # 4挨着挨着的状态的位置
    npos = nx*self.col+ny
    if not (nx>=0 and nx<self.col and ny>=0 and ny<self.col):
     continue
    # python中字符串不可更改，于是把字符串变成list更改状态后再转换为字符串
    if sta[pos] == '2' and sta[npos] == '0' and self.en[npos] != '1':
    # 人和箱子一起推动，sta中连着的状态为4 2 0，en中第三个不能为1。推完之后sta变为0 4 2
     digits = [int(x) for x in sta]
     digits[ppos],digits[pos],digits[npos] = 0,4,2
     new_sta = ''.join(str(x) for x in digits)
     if new_sta not in visi:
      visi[new_sta] = 1
      states.append([new_sta, path+dir[3], cx, cy])
    elif sta[pos] == '0' and self.en[pos] !='1':
    # 人动箱子不动，sta中连着的状态为4 0，en中第二个不能为1。
     digits = [int(x) for x in sta]
     digits[ppos], digits[pos] = 0, 4
     new_sta = ''.join(str(x) for x in digits)
     if new_sta not in visi:
      visi[new_sta] = 1
      states.append([new_sta, path + dir[2], cx, cy])
 
if __name__ == '__main__':
 f = open(level_file_path, encoding='utf-8')
 cnt = 0
 while(1):
  line = f.readline()
  line = line.strip('\n')
  if len(line)==0 :
   break
  gs = GameShortest(line)
 
"""
level_file.txt中内容:
1111111111111111111111100011111110221111111420111111111001111111300111111330011111111111111111111111
1111111111104000000110000200111001101011100100101110010010111001011001110030000111111111111111111111
1111111111111111111111111111111110311111140020001110230020111111311111111111111111111111111111111111
1111111111111111111111100011111110221111111013311111102301111110040111111111111111111111111111111111
1111111111111111111111111111111100000111112111001113030020111400100011111111111111111111111111111111
1111111111111111111111111111111110011111100000011111001220111140300311111111111111111111111111111111
1111111111110040001110000000111001110011110011001111020130111100002011111311111111111111111111111111
1111111111111111111111111111111100111111100320001110131210111000000411111111111111111111111111111111
1111111111111111111111111111111100000111100111011110002020111000133411111111111111111111111111111111
1111111111111111111111100111111110004111111101011111312100111132001011113000201111111111111111111111
1111111111111111111111000001111131103111110402011111001201111100100111111111111111111111111111111111
1111111111111111111111100001111113112011110234001111001000111100001111111111111111111111111111111111
1111111111111111111111111001111110204111111020011111300101111130000111111111111111111111111111111111
1111111111111111111111143001111100000111110010211111001203111111101011111110001111111111111111111111
1111111111111111111111111111111100001111110202111111033420111111130011111111111111111111111111111111
1111111111111111111111110001111100230111114032301111110120111111000111111111111111111111111111111111
1111111111111111111111110031111102010111110020011111031401111100001111111111111111111111111111111111
1111111111111111111111111104111113110011110330201111021200111100001111111111111111111111111111111111
1111111111111111111111000111111100330111110011211111100100111112000411111001111111111111111111111111
1111111111111111111111100001111103032111110024001111111010111111100011111111111111111111111111111111
每一关的最短路径:
['uurrDDDDuuuulldRurDDDrddLLrruLuuulldRurDDDrdL']
['drrRRurDDDDDrdLLL']
['rrdrUrrrdLLulDullldR']
['lluRRdrUllluuurrDDuulldRurD']
['urrrrdrruulullllDurrrrdrddllullLrrrdrruLLL']
['uurrrrDulllddrrRuulDrdL']
['drrdddrdLLLuLDlUUUluRRRRurDDD']
['uullLLddrrUdlllluuRurDrRddrruuLLL']
['lUlLLdlluururrrrDDrdLullldlluRRRRllluurrrrdD']
['ddrddLLulLdlUrrrdrruuluulldDuurrddrddllLLrruLL']
['luurrrdrdLLLrrrddlUruuulllldDrddlUUrrRdrU']
['ddlluluRuurrrDrddlluLrdrruLLddlluU']
['dddlluluuRDrruulDrdLLulDrDLurrrddlLL']
['drrdDrrddllUUUUruLdrDldR', 'drrdDrrddllUUUUrDldRuuuL']
['drruLLLuulldRurDurDD']
['urRdddrrUULLulldRururrD']
['uLrddlluluuRDrrruullDldRRdrUU']
['dddlUllllddrUUddrrUruLLrrruulDrdLL']
['llldlUUUluurDrrrDDrdLLLulUluRRlddrddlUUUluR']
['ulldRurDrrddllUUluurrDLLdrddrruuLrddlluU']
"""