# -*- coding: UTF-8 -*-
'''
Created on 2017年6月9日@author: LXu4
'''
import copy
import time
class Soduku(object):def __init__(self, problem):self.problem = problemdef resolve(self):solutionStack = [self.problem]tmp = self.get_solution_array(self.problem)solutionArrayStack = [tmp]time_t = 0prev_x = -1prev_y = -1while 1:# time_t += 1# fetch the last solution in solution stacknext_item_cord = {}solutionArray = []# print 'still ',len(solutionStack),'in stack'solutionNow = copy.deepcopy(solutionStack[len(solutionStack) - 1])solutionArray = solutionArrayStack[len(solutionArrayStack) - 1]flag = self.check_if_need_to_back(solutionNow, solutionArray)if flag is True:# print 'pop!'
                solutionArrayStack.pop()solutionStack.pop()else:time_t += 1# next_item_cord = self.get_first_possible_item(solutionArray,solutionNow=solutionNow)next_item_cord = self.get_first_possible_item(solutionArray,solutionNow=solutionNow)if next_item_cord == False:break# print 'next_item_cord:',next_item_cordprev_x = next_item_cord['x']prev_y = next_item_cord['y']next_item_array = solutionArray[prev_x][prev_y]next_item = next_item_array[len(next_item_array)-1]# randint(0,len(next_item_array)-1)solutionNow[prev_x][prev_y] = next_item# solutionArray_tmp = get_solution_array(solutionNow)solutionArray_tmp = copy.deepcopy(solutionArray)solutionArray_tmp = self.get_resolution_array_new(solutionArray_tmp, prev_x, prev_y,next_item)if next_item in solutionArray[prev_x][prev_y]:solutionArray[prev_x][prev_y].remove(next_item)# print 'next point is ',prev_x,',',prev_y
                solutionStack.append(solutionNow)solutionArrayStack.append(solutionArray_tmp)# print solutionArrayStack# print solutionStackfor i in range(0, 9, 1):print solutionStack[len(solutionStack) - 1][i]print 'total forward:',time_tdef check_if_need_to_back(self,solutionNow, solutionArray):for i in range(0, 9, 1):for j in range(0, 9, 1):if len(solutionArray[i][j]) == 0 and solutionNow[i][j] == 0:return Truereturn Falsedef get_resolution_array_new(self,solutionArray, x, y, value):for tmp_j in range(0, 9, 1):if value in solutionArray[x][tmp_j]:solutionArray[x][tmp_j].remove(value)for tmp_i in range(0, 9, 1):if value in solutionArray[tmp_i][y]:solutionArray[tmp_i][y].remove(value)for tmp_i in range(x / 3 * 3, x / 3 * 3 + 3):for tmp_j in range(y / 3 * 3, y / 3 * 3 + 3):if value in solutionArray[tmp_i][tmp_j]:solutionArray[tmp_i][tmp_j].remove(value)return solutionArraydef get_solution_array(self,problem):tmp = []for i in range(0, 9, 1):tmp_line_array = []for j in range(0, 9, 1):# print '['+bytes(i)+','+bytes(j)+']: '+ bytes(problem[i][j])if problem[i][j] == 0:# no value, get possible value arraytmp_value = [1, 2, 3, 4, 5, 6, 7, 8, 9]# remove the existed value in linefor tmp_j in range(0, 9, 1):if problem[i][tmp_j] != 0:if problem[i][tmp_j] in tmp_value:tmp_value.remove(problem[i][tmp_j])# remove the existed value in columnfor tmp_i in range(0, 9, 1):if problem[tmp_i][j] != 0:if problem[tmp_i][j] in tmp_value:tmp_value.remove(problem[tmp_i][j])# remove the existed value in the rectanglefor x in range(i / 3 * 3, i / 3 * 3 + 3):for y in range(j / 3 * 3, j / 3 * 3 + 3):if problem[x][y] != 0:if problem[x][y] in tmp_value:tmp_value.remove(problem[x][y])tmp_line_array.append(tmp_value)else:tmp_line_array.append([])tmp.append(tmp_line_array)# print tmp_line_array# print tmpreturn tmp# get first item to be the point of treedef get_first_possible_item(self, solution_array, solutionNow = None):is_finished = Trueshortest_item_length = 9shortest_item_x = 0shortest_item_y = 0for i in range(0, 9, 1):for j in range(0, 9, 1):tmp_length = len(solution_array[i][j])if tmp_length != 0:is_finished = Falseif solutionNow[i][j] != 0:tmp_length += 1if tmp_length < shortest_item_length:shortest_item_length = tmp_lengthshortest_item_x = ishortest_item_y = j# print 'shortest item is:',shortest_item_length,shortest_item_x,shortest_item_yif is_finished:return Falseelse:return {'x': shortest_item_x, 'y': shortest_item_y}def get_next_possible_item(self, solution_array, prev_x, prev_y, solutionNow = None):if prev_x == -1 and prev_y == -1:return self.get_first_possible_item(solution_array, solutionNow)else:is_finished = Trueshortest_item_length = 9shortest_item_x = 0shortest_item_y = 0for tmp_i in range(0, 9, 1):tmp_length = len(solution_array[tmp_i][prev_y])if tmp_length != 0:is_finished = Falseif solutionNow[tmp_i][prev_y] != 0:tmp_length += 1if tmp_length < shortest_item_length:shortest_item_length = tmp_lengthshortest_item_x = tmp_ishortest_item_y = prev_yif tmp_length == 1:return {'x': shortest_item_x, 'y': shortest_item_y}for tmp_j in range(0, 9, 1):tmp_length = len(solution_array[prev_x][tmp_j])if tmp_length != 0:is_finished = Falseif solutionNow[prev_x][tmp_j] != 0:tmp_length += 1if tmp_length < shortest_item_length:shortest_item_length = tmp_lengthshortest_item_x = prev_xshortest_item_y = tmp_jif tmp_length == 1:return {'x': shortest_item_x, 'y': shortest_item_y}for x in range(prev_x / 3 * 3, prev_x / 3 * 3 + 3):for y in range(prev_y / 3 * 3, prev_y / 3 * 3 + 3):tmp_length = len(solution_array[x][y])if tmp_length != 0:is_finished = Falseif solutionNow[x][y] != 0:tmp_length += 1if tmp_length < shortest_item_length:shortest_item_length = tmp_lengthshortest_item_x = xshortest_item_y = yif tmp_length == 1:return {'x': shortest_item_x, 'y': shortest_item_y}# print 'shortest item is:',shortest_item_length,shortest_item_x,shortest_item_yif is_finished:return self.get_first_possible_item(solution_array,solutionNow)else:return {'x': shortest_item_x, 'y': shortest_item_y}problem = \[[3,0,8,0,0,0,6,0,0],  [0,4,0,0,6,5,0,0,7],  [7,0,0,4,3,0,0,9,0],  [0,0,7,0,0,1,5,8,0],  [1,0,0,0,2,0,0,0,9],  [0,9,4,7,0,0,2,0,0],  [8,0,0,0,7,4,0,0,0],  [4,0,0,6,5,0,8,1,0],  [0,0,9,0,0,0,7,0,2]      ]f = Soduku(problem)
startTime=time.time()
f.resolve()
endTime=time.time()
print "Finished! Time consuming: " + "%.4f" % (endTime-startTime) + " Seconds"