Sudoku Solver - JavaScript Coding Challenge

Write a program to solve a Sudoku puzzle by filling the empty cells.

Sample Input:

[["5","3",".",".","7",".",".",".","."],["6",".",".","1","9","5",".",".","."],[".","9","8",".",".",".",".","6","."],["8",".",".",".","6",".",".",".","3"],["4",".",".","8",".","3",".",".","1"],["7",".",".",".","2",".",".",".","6"],[".","6",".",".",".",".","2","8","."],[".",".",".","4","1","9",".",".","5"],[".",".",".",".","8",".",".","7","9"]]

Sample Output:

[["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","1","9"],["7","1","3","9","2","4","8","5","6"],["9","8","5","2","1","7","6","3","4"],["2","4","1","3","6","5","8","7","9"],["3","6","7","4","8","9","1","2","5"]]

Hints

Hint 1

Use backtracking to try different numbers

Hint 2

Check row, column, and 3x3 box constraints

Hint 3

Use recursion to explore possibilities