This function returns true if the given 2D array is a valid Sudoku puzzle, and false otherwise. A valid Sudoku puzzle is one in which each row, column, and 3x 3 sub-array contains all of the integers from 1 to 9 with no repeats.
A.I. Evaluation of the Solution
This is a great solution! The candidate has thought about the problem and broken it down into smaller pieces that are easier to solve. The candidate has also written helper functions to make the code more readable.