/// <summary>
/// Parses the text representing a single <see cref="SudokuPuzzle"/>.
/// </summary>
/// <param name="s">The text to parse.</param>
/// <returns>A <see cref="SudokuPuzzle"/> representation of <c><paramref name="s"/></c>.</returns>
/// <exception cref="ArgumentNullException"><c><paramref name="s"/></c> is <c>null</c>.</exception>
/// <exception cref="FormatException"><c><paramref name="s"/></c> is not in the correct format.</exception>
public static SudokuPuzzle Deserialize(String s)
{
if (s is null)
{
throw new ArgumentNullException(nameof(s));
}
String[] split = s.Split(',');
if (split.Length != 5)
{
throw new FormatException();
}
try
{
int size = Int32.Parse(split[0]);
int squared = size * size;
if (!SudokuPuzzle.VerifySize(size))
{
throw new FormatException();
}
SudokuDifficulty difficulty = (SudokuDifficulty)Enum.Parse(typeof(SudokuDifficulty), split[1], true);
int[] numbers = new int[squared], solutions = new int[squared];
bool[] readOnly = new bool[squared];
if (split[2].Length != squared || split[3].Length != squared || split[4].Length != squared)
{
throw new FormatException();
}
for (int i = 0; i < squared; i++)
{
numbers[i] = split[2][i] - '0';
solutions[i] = split[3][i] - '0';
readOnly[i] = split[3][i] == '1';
}
SudokuPuzzle puzzle = SudokuPuzzle.Parse(size, difficulty, numbers, solutions, readOnly);
puzzle.ResetPossible();
return(puzzle);
}
catch
{
throw new FormatException();
}
}
/// <summary>
/// Converts the string representation to its <see cref="SudokuPuzzle"/> equivalent.
/// </summary>
/// <param name="s">A string containing a puzzle to convert.</param>
/// <param name="difficulty">An optional difficulty to associate with the <see cref="SudokuPuzzle"/>.</param>
/// <returns>A <see cref="SudokuPuzzle"/> equivalent to the puzzle contained in <c><paramref name="s"/></c>.</returns>
/// <exception cref="ArgumentNullException"><c><paramref name="s"/></c> is <c>null</c>.</exception>
/// <exception cref="FormatException"><c><paramref name="s"/></c> is not in the correct format.</exception>
public static SudokuPuzzle Parse(String s, SudokuDifficulty difficulty = SudokuDifficulty.None)
{
if (s is null)
{
throw new ArgumentNullException(nameof(s));
}
s = Regex.Replace(s, @"[^0-9]", "");
int size = (int)Math.Sqrt(s.Length);
if (!SudokuPuzzle.VerifySize(size))
{
throw new FormatException();
}
SudokuPuzzle sudoku;
try
{
sudoku = new SudokuPuzzle(size, difficulty);
}
catch
{
throw new FormatException();
}
for (int i = 0; i < size; i++)
{
int currentRow = i * size;
for (int j = 0; j < size; j++)
{
sudoku[i, j] = s[currentRow + j] - '0';
}
}
return(sudoku);
}