The following Python program solves Sudoku using backtracking. The method that starts the solution is "solve_sudoku(matrix)" and receives as input an n x n matrix where the empty inputs are...

The following Python program solves Sudoku using backtracking. The method that starts the solution is "solve_sudoku(matrix)" and receives as input an n x n matrix where the empty inputs are represented by -1

from pprint import pprint

def search_next_void(puzzle):
    for r in range(9):
        for c in range(9):
            if puzzle[r][c] == -1:
                return r, c

    return None, None

def is_valid(puzzle, guess, row, col):
    row_vals = puzzle[row]
    if guess in row_vals:
        return False

    col_vars = [puzzle[i][col] for i in range(9)]
        if guess in col_vars:
            return False

    row_start = (row // 3) * 3
    col_start = (col // 3) * 3

    for r in range(row_start, row_start + 3):
        for c in range(col_start, col_start + 3):
            if puzzle[r][c] == guess:
                return False

    return True

def solve_sudoku(puzzle):
    row, col = search_next_void(puzzle)
    if row is None:
        return True

    for guess in range(1, 10):
        if is_valid(puzzle, guess, row, col):
            print(board_example)
            print("\n")
            puzzle[row][col] = guess


           if solve_sudoku(puzzle):
                return True

    puzzle[row][col] = -1

    return False

Find the first solution for the image data