# basic_valid_sudoku_gen2.py

# basic_valid_sudoku_gen2.py

import random
import time

level = (36, 30, 27, 24, 21, 18) # (0 to 5) from easy to expert

aaa='abcdefghxdgfxhabcehxecgbfdafedgxhabcxhgabcefdbcaefdxgheahbdgcxfgdxfcehabcfbhaxdeg'
bbb='..X.X.X..X.X......X.........X..X..X........XX........X.X....X..X..X........X.....'
grid=range(81)
numbers=range(1,10)

hints = level[5]
def progress(z):
    for i in range(9):
        print
        for ii in range(9):
            print z[i*9+ii],
    print
    print
def shfl(z):
    z=[[z[i*9+ii] for i in range(9)] for ii in range(9)]
    z=[z[0:3],z[3:6],z[6:9]]
    for i in range(3):
        random.shuffle(z[i])
    random.shuffle(z)
    return sum(sum(z,[]),[])
def init():
    sq=grid
    random.shuffle(numbers) # for an added measure
    for i in range(numbers[-1]):
        sq=shfl(sq)
    a=b=''
    for i in sq:
        a+=aaa[i]
        b+=bbb[i]
    for i in range(9):
        tmp=str(numbers[i])
        a=a.replace(a[i],tmp)
        b=b.replace(a[i],tmp)
    random.shuffle(sq)
    b=list(b)
    for i in sq:
        if b[i] is 'X': b[i]=a[i]
        elif 81-b.count('.') < hints: b[i]=a[i]
    progress(a)
    progress(b)
    print 81-b.count('.'), 'hints'
    print
    print ''.join(b)
#
init()