public void EmbedSecretData(byte[] containerBytes, byte[] secretBytes, SudokuMatrix <byte> sudokuKey)
{
if (containerBytes == null || containerBytes.Length == 0 || secretBytes == null || secretBytes.Length == 0)
{
throw new ArgumentException();
}
if (secretBytes.Length * 2 >= containerBytes.Length)
{
throw new InvalidOperationException("Cannot encrypt secret data because container image is too small");
}
ValidateSudoku(sudokuKey);
for (int i = 0, secretDataIterator = 0;
i + 1 < containerBytes.Length && secretDataIterator < secretBytes.Length;
i += 2, secretDataIterator++)
{
byte currentByte = secretBytes[secretDataIterator];
SudokuCoordinates initialCoordinates = new SudokuCoordinates(containerBytes[i], containerBytes[i + 1]);
SudokuCoordinates nearestCoordinates = sudokuKey.FindNearestCoordinates(currentByte, initialCoordinates);
if (initialCoordinates != nearestCoordinates)
{
containerBytes[i] = nearestCoordinates.X;
containerBytes[i + 1] = nearestCoordinates.Y;
}
}
}
public SudokuCoordinates Find(T valueToFind, SudokuCoordinates initialCoordinates, T[,] sudokuMatrix)
{
int sudokoSize = sudokuMatrix.GetLength(0);
if (!(//valueToFind >= 0 && valueToFind < sudokoSize &&
initialCoordinates.X >= 0 && initialCoordinates.X < sudokoSize &&
initialCoordinates.Y >= 0 && initialCoordinates.Y < sudokoSize))
{
throw new ArgumentException("Wrong initialCoordinates or valueToFind");
}
int sudokoBlockSize = (int)Math.Sqrt(sudokoSize);
//depth 0
if (CheckValue(initialCoordinates.X, initialCoordinates.Y, valueToFind, sudokoSize, sudokuMatrix))
{
return(initialCoordinates);
}
for (int depth = 1; depth <= sudokoBlockSize * 2 + 2; depth++)
{
for (int i = 0; i < depth + 1; i++)
{
int offset = (depth - i);
int x1 = initialCoordinates.X + i;
int y1 = initialCoordinates.Y + offset;
if (CheckValue(x1, y1, valueToFind, sudokoSize, sudokuMatrix))
{
return(new SudokuCoordinates((byte)x1, (byte)y1));
}
int x2 = initialCoordinates.X + i;
int y2 = initialCoordinates.Y - offset;
if (CheckValue(x2, y2, valueToFind, sudokoSize, sudokuMatrix))
{
return(new SudokuCoordinates((byte)x2, (byte)y2));
}
int x3 = initialCoordinates.X - i;
int y3 = initialCoordinates.Y + offset;
if (CheckValue(x3, y3, valueToFind, sudokoSize, sudokuMatrix))
{
return(new SudokuCoordinates((byte)x3, (byte)y3));
}
int x4 = initialCoordinates.X - i;
int y4 = initialCoordinates.Y - offset;
if (CheckValue(x4, y4, valueToFind, sudokoSize, sudokuMatrix))
{
return(new SudokuCoordinates((byte)x4, (byte)y4));
}
}
}
throw new Exception($"Cannot find requested value: {valueToFind} in the sudoku matrix.");
}
