# Write a function that will solve a 9x9 Sudoku puzzle. The function will take one argument consisting of the 2D
# puzzle array, with the value 0 representing an unknown square.
#
# The Sudokus tested against your function will be "easy" (i.e. determinable; there will be no need to assume and
# test possibilities on unknowns) and can be solved with a brute-force approach.
#
# For Sudoku rules, see the Wikipedia article.

def sudoku(puzzle):
    """return the solved puzzle as a 2d array of 9 x 9"""

    return puzzle



# puzzle = [[5,3,0,0,7,0,0,0,0],
#           [6,0,0,1,9,5,0,0,0],
#           [0,9,8,0,0,0,0,6,0],
#           [8,0,0,0,6,0,0,0,3],
#           [4,0,0,8,0,3,0,0,1],
#           [7,0,0,0,2,0,0,0,6],
#           [0,6,0,0,0,0,2,8,0],
#           [0,0,0,4,1,9,0,0,5],
#           [0,0,0,0,8,0,0,7,9]]
# sudoku(puzzle)
# # Should return
#  [[5,3,4,6,7,8,9,1,2],
#   [6,7,2,1,9,5,3,4,8],
#   [1,9,8,3,4,2,5,6,7],
#   [8,5,9,7,6,1,4,2,3],
#   [4,2,6,8,5,3,7,9,1],
#   [7,1,3,9,2,4,8,5,6],
#   [9,6,1,5,3,7,2,8,4],
#   [2,8,7,4,1,9,6,3,5],
#   [3,4,5,2,8,6,1,7,9]]