python实现解数独程序的代码示例

 #coding=utf-8
 import datetime
 class solution(object):
   def __init__(self,board):
     self.b = board
     self.t = 0
 
   def check(self,x,y,value):#检查每行每列及每宫是否有相同项
     for row_item in self.b[x]:
       if row_item == value:
         return False
     for row_all in self.b:
       if row_all[y] == value:
         return False
     row,col=x/3*3,y/3*3
     row3col3=self.b[row][col:col+3]+self.b[row+1][col:col+3]+self.b[row+2][col:col+3]
     for row3col3_item in row3col3:
       if row3col3_item == value:
         return False
     return True
 
   def get_next(self,x,y):#得到下一个未填项
     for next_soulu in range(y+1,9):
       if self.b[x][next_soulu] == 0:
         return x,next_soulu
     for row_n in range(x+1,9):
       for col_n in range(0,9):
         if self.b[row_n][col_n] == 0:
           return row_n,col_n
     return -1,-1 #若无下一个未填项，返回-1
 
   def try_it(self,x,y):#主循环
     if self.b[x][y] == 0:
       for i in range(1,10):#从1到9尝试
         self.t+=1
         if self.check(x,y,i):#符合 行列宫均无条件 的
           self.b[x][y]=i #将符合条件的填入0格
           next_x,next_y=self.get_next(x,y)#得到下一个0格
           if next_x == -1: #如果无下一个0格
             return True #返回True
           else:    #如果有下一个0格，递归判断下一个0格直到填满数独
             end=self.try_it(next_x,next_y)
             if not end:  #在递归过程中存在不符合条件的，即 使try_it函数返回None的项
               self.b[x][y] = 0  #回朔到上一层继续
             else:
               return True
 
   def start(self):
     begin = datetime.datetime.now()
     if self.b[0][0] == 0:
       self.try_it(0,0)
     else:
       x,y=self.get_next(0,0)
       self.try_it(x,y)
     for i in self.b:
       print i
     end = datetime.datetime.now()
     print '\ncost time:', end - begin
     print 'times:',self.t
     return
 
 
 s=solution([[8,0,0,0,0,0,0,0,0],
     [0,0,3,6,0,0,0,0,0],
     [0,7,0,0,9,0,2,0,0],
     [0,5,0,0,0,7,0,0,0],
     [0,0,0,8,4,5,7,0,0],
     [0,0,0,1,0,0,0,3,0],
     [0,0,1,0,0,0,0,6,8],
     [0,0,8,5,0,0,0,1,0],
     [0,9,0,0,0,0,4,0,0]])
 73 s.start()

[8, 1, 2, 7, 5, 3, 6, 4, 9]
[9, 4, 3, 6, 8, 2, 1, 7, 5]
[6, 7, 5, 4, 9, 1, 2, 8, 3]
[1, 5, 4, 2, 3, 7, 8, 9, 6]
[3, 6, 9, 8, 4, 5, 7, 2, 1]
[2, 8, 7, 1, 6, 9, 5, 3, 4]
[5, 2, 1, 9, 7, 4, 3, 6, 8]
[4, 3, 8, 5, 2, 6, 9, 1, 7]
[7, 9, 6, 3, 1, 8, 4, 5, 2]

cost time: 0:00:00.060687
times: 45360