这是一道数独题第一次碰见想写一下wp

此题是2021moectf的题目

拖入ida看看

cheak123是关键函数

分别进去看看

cheak1 判断每一横排的数字为1-9不重复

cheak2 判断每一竖排的数字为1-9不重复

cheak3 判断九宫格里的数字为1-9且不重复

然后知道这是一道数独， 如下

box = [0x00, 0x00, 0x05, 0x00, 0x00, 0x04, 0x03, 0x06, 0x00,
       0x00, 0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x02, 0x04,
       0x00, 0x04, 0x09, 0x06, 0x07, 0x00, 0x00, 0x00, 0x00,
       0x01, 0x00, 0x06, 0x00, 0x02, 0x00, 0x00, 0x03, 0x00,
       0x09, 0x00, 0x00, 0x07, 0x00, 0x00, 0x01, 0x00, 0x08,
       0x00, 0x03, 0x00, 0x00, 0x00, 0x05, 0x00, 0x09, 0x00,
       0x02, 0x00, 0x00, 0x05, 0x00, 0x07, 0x00, 0x00, 0x09,
       0x07, 0x00, 0x04, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00,
       0x00, 0x09, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x06]

可以用数独在线求解器或者z3约束器来求解

下面写个z3

from z3 import *

X = [ [ Int("x_%s_%s" % (i+1, j+1)) for j in range(9) ]
      for i in range(9) ]

cells_c  = [ And(1 <= X[i][j], X[i][j] <= 9)
             for i in range(9) for j in range(9) ]


rows_c   = [ Distinct(X[i]) for i in range(9) ]

cols_c   = [ Distinct([ X[i][j] for i in range(9) ])
             for j in range(9) ]


sq_c     = [ Distinct([ X[3*i0 + i][3*j0 + j]
                        for i in range(3) for j in range(3) ])
             for i0 in range(3) for j0 in range(3) ]

sudoku_c = cells_c + rows_c + cols_c + sq_c

instance = [[0x00, 0x00, 0x05, 0x00, 0x00, 0x04, 0x03, 0x06, 0x00],
            [0x00, 0x00, 0x00, 0x00, 0x05, 0x00, 0x00, 0x02, 0x04],
            [0x00, 0x04, 0x09, 0x06, 0x07, 0x00, 0x00, 0x00, 0x00],
            [0x01, 0x00, 0x06, 0x00, 0x02, 0x00, 0x00, 0x03, 0x00],
            [0x09, 0x00, 0x00, 0x07, 0x00, 0x00, 0x01, 0x00, 0x08],
            [0x00, 0x03, 0x00, 0x00, 0x00, 0x05, 0x00, 0x09, 0x00],
            [0x02, 0x00, 0x00, 0x05, 0x00, 0x07, 0x00, 0x00, 0x09],
            [0x07, 0x00, 0x04, 0x00, 0x00, 0x00, 0x08, 0x00, 0x00],
            [0x00, 0x09, 0x00, 0x00, 0x04, 0x00, 0x00, 0x00, 0x06]]

instance_c = [ If(instance[i][j] == 0,
                  True,
                  X[i][j] == instance[i][j])
               for i in range(9) for j in range(9) ]

s = Solver()
s.add(sudoku_c + instance_c)
if s.check() == sat:
    m = s.model()
    r = [ [ m.evaluate(X[i][j]) for j in range(9) ]
          for i in range(9) ]
    print_matrix(r)
else:
    print("failed to solve")

官网文档有可以直接白嫖，然后自己可以复现一下

官网文档

得到

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