Have you ever dealt with solving Sudoku puzzles in your practice or training?

Yes, I have solved Sudoku puzzles both for educational purposes and to practice algorithmic thinking. This usually involves implementing a backtracking algorithm that tries different options for filling the cells, checking the Sudoku rules. This approach helps understand recursion and optimization of the search.

A simplified example of the algorithm in Java:

boolean solveSudoku(int[][] board) {
    for (int row = 0; row < 9; row++) {
        for (int col = 0; col < 9; col++) {
            if (board[row][col] == 0) { // empty cell
                for (int num = 1; num <= 9; num++) {
                    if (isValid(board, row, col, num)) {
                        board[row][col] = num;
                        if (solveSudoku(board)) {
                            return true;
                        }
                        board[row][col] = 0; // backtrack
                    }
                }
                return false; // no solution
            }
        }
    }
    return true; // solved
}