def __init__(self, squares):
"""Squares is a nested list representing an initial sudoku board. A 0
represents an empty square, while a nonzero digit represents a square
filled with that value."""
self.dlxrows = squares_to_dlx_rows(squares)
sparseMatrix = SparseMatrix(self.dlxrows)
self.dlx = DLX(sparseMatrix)
def testSearch(self):
matrix = SparseMatrix(rows1)
dlx = DLX(matrix)
result = dlx.search()
assert result
mat2 = SparseMatrix(rows2)
dlx2 = DLX(mat2)
result2 = dlx2.search()
assert not result2
mat3 = SparseMatrix(rows3)
dlx3 = DLX(mat3)
res3 = dlx3.search()
assert res3
mat4 = SparseMatrix(rows4)
dlx4 = DLX(mat4)
res4 = dlx4.search()
assert res4
def testChooseColumn(self):
matrix = SparseMatrix(rows1)
dlx = DLX(matrix)
coltable = matrix.column_table
column = dlx.choose_column()
assert coltable[0] == column
matrix.cover(column)
# See Figure 3; column D now only has one node in it.
after_cover = dlx.choose_column()
assert coltable[3] == after_cover
