Sudoku

Write a program to solve a Sudoku puzzle by filling the empty cells.
Empty cells are indicated by the character '.'
You may assume that there will be only one unique solution.

A sudoku puzzle,

and its solution numbers marked in red.

Note: You must update the input argument A (partially completed grid of Sudoku) to submit your solved Sudoko grid.

Example :

For the above given diagrams, the corresponding input to your program will be

[[53..7....], [6..195...], [.98....6.], [8...6...3], [4..8.3..1], [7...2...6], [.6....28.], [...419..5], [....8..79]]

and we would expect your program to modify the above array of array of characters to

[[534678912], [672195348], [198342567], [859761423], [426853791], [713924856], [961537284], [287419635], [345286179]]

NOTE: You only need to implement the given function. Do not read input, instead use the arguments to the function. Do not print the output, instead return values as specified. Still have a question? Checkout Sample Codes for more details.