/// <summary>
/// Show ArgumentNullException and ArgumentException messages using Log4Net.
/// </summary>
public static void ShowExceptions()
{
BasicConfigurator.Configure();
try
{
int size = 3;
int[,] matrix = new int[size, size];
int currentValue = 1;
Cell cell = new Cell(0, 0);
Direction direction = PossibleDirections.GetInitialDirection();
currentValue = MatrixTraversal.FillMatrix(matrix, currentValue, cell, direction);
cell = MatrixTraversal.FindEmptyCell(matrix);
currentValue++;
direction = PossibleDirections.GetInitialDirection();
MatrixTraversal.FillMatrix(matrix, currentValue, cell, direction);
}
catch (ArgumentNullException ane)
{
exceptionError.Error(
"This message is thrown by method Log4Net.ShowExceptions() \r\n" +
ane.Message);
}
catch (ArgumentException ae)
{
exceptionError.Error(
"This message is thrown by method Log4Net.ShowExceptions() \r\n" +
ae.Message);
}
}
/// <summary>
/// Traverse a matrix using console for input/output
/// </summary>
/// <remarks>Use Log4Net to show the exeption messages.
/// The method Log4Net.ShowExceptions is designed to cause
/// ArgumentNullException for demonstration</remarks>
public static void Main()
{
BasicConfigurator.Configure();
try
{
int size = ConsoleIO.ReadInput();
int[,] matrix = new int[size, size];
int currentValue = 1;
Cell cell = new Cell(0, 0);
Direction direction = PossibleDirections.GetInitialDirection();
currentValue = MatrixTraversal.FillMatrix(matrix, currentValue, cell, direction);
cell = MatrixTraversal.FindEmptyCell(matrix);
if (currentValue < size * size)
{
currentValue++;
direction = PossibleDirections.GetInitialDirection();
MatrixTraversal.FillMatrix(matrix, currentValue, cell, direction);
}
ConsoleIO.PrintMatrix(matrix);
}
catch (ArgumentNullException ane)
{
exceptionError.Error(ane.Message, ane);
}
catch (ArgumentException ae)
{
exceptionError.Error(ae.Message, ae);
}
// Designed to couse ArgumentNullException for demonstration
// This method throws the ERROR messages on the console
Log4Net.ShowExceptions();
}
/// <summary>
/// Fill matrix with numbers
/// operation
/// </summary>
/// <param name="matrix">2D array</param>
/// <param name="startingCell">first empty cell</param>
private static void FillMatrix(int[,] matrix, Cell startingCell)
{
var cell = startingCell;
var index = 0;
while (IsCellUsable(matrix, cell))
{
matrix[cell.X, cell.Y] = cell.Value;
while (!IsNextCellUsable(matrix, cell, index) &&
HasAvailableMove(matrix, cell, index))
{
index = (index + 1) % DirectionX.Length;
}
cell.X += DirectionX[index];
cell.Y += DirectionY[index];
cell.Value++;
}
// Calls FillMatrix recursively with next empty cell if exists
var nextCell = FindEmptyCell(matrix);
if (nextCell != null)
{
nextCell.Value = cell.Value;
FillMatrix(matrix, nextCell);
}
}
/// <summary>
/// Assign cells in a matrix
/// </summary>
/// <param name="matrix">Matrix, which cells are going to be assigned</param>
/// <param name="currentValue">Initial value to assign the first unassigned cell</param>
/// <param name="cell">Initial cell from which start the assigning</param>
/// <param name="direction">Initial direction to traverse the matrix</param>
/// <exception cref="ArgumentNullException">
/// If there is not initialized input parameter</exception>
/// <exception cref="ArgumentException">
/// If we try to assign a cell with non-positive value</exception>
/// <returns>Value of last assigned cell</returns>
public static int FillMatrix(int[,] matrix, int currentValue, Cell cell, Direction direction)
{
if (matrix == null || cell == null || direction == null)
{
throw new ArgumentNullException(
"Invalid input! You cannot fill matrix using empty (null) parameter.");
}
if (currentValue < 1)
{
throw new ArgumentException(
"Invalid input! You cannot fill matrix with non-positive number.");
}
matrix[cell.Row, cell.Column] = currentValue;
while (IsPath(matrix, cell))
{
direction = FindDirection(matrix, cell, direction);
cell.Row += direction.X;
cell.Column += direction.Y;
currentValue++;
matrix[cell.Row, cell.Column] = currentValue;
}
return currentValue;
}
public void TestFillMatrixNegativeValue()
{
int[,] matrix = new int[3, 3];
int currentValue = -1;
Cell cell = new Cell(0, 0);
Direction direction = PossibleDirections.GetInitialDirection();
MatrixTraversal.FillMatrix(matrix, currentValue, cell, direction);
}
/// <summary>
/// Search for first empty cell in
/// 2D array
/// </summary>
/// <param name="matrix">2D array</param>
/// <returns>null if empty Cell does not exist,
/// or new Cell</returns>
private static Cell FindEmptyCell(int[,] matrix)
{
for (int row = 0; row <= matrix.GetUpperBound(0); row++)
{
for (int col = 0; col <= matrix.GetUpperBound(1); col++)
{
if (matrix[row, col] == 0)
{
var emptyCell = new Cell(row, col);
return emptyCell;
}
}
}
return null;
}
public void TestFillMatrixHalf()
{
int[,] matrix = new int[5, 5];
int currentValue = 1;
Cell cell = new Cell(0, 0);
Direction direction = PossibleDirections.GetInitialDirection();
MatrixTraversal.FillMatrix(matrix, currentValue, cell, direction);
int[,] result = {
{1,13,14,15,16},
{12,2,21,22,17},
{11,0,3,20,18},
{10,0,0,4,19},
{9,8,7,6,5}
};
Assert.AreEqual(result[2, 3], matrix[2, 3]);
Assert.AreEqual(result[0, 4], matrix[0, 4]);
Assert.AreEqual(result[2, 1], matrix[2, 1]);
Assert.AreEqual(result[3, 1], matrix[3, 1]);
Assert.AreEqual(result[3, 2], matrix[3, 2]);
}
public void TestFillMatrix()
{
int[,] matrix = new int[3, 3];
int currentValue = 1;
Cell cell = new Cell(0, 0);
Direction direction = PossibleDirections.GetInitialDirection();
MatrixTraversal.FillMatrix(matrix, currentValue, cell, direction);
int[,] result = {
{1,7,8},
{6,2,9},
{5,4,3},
};
Assert.AreEqual(result[0, 0], matrix[0, 0]);
Assert.AreEqual(result[0, 1], matrix[0, 1]);
Assert.AreEqual(result[0, 2], matrix[0, 2]);
Assert.AreEqual(result[1, 0], matrix[1, 0]);
Assert.AreEqual(result[1, 1], matrix[1, 1]);
Assert.AreEqual(result[1, 2], matrix[1, 2]);
Assert.AreEqual(result[2, 0], matrix[2, 0]);
Assert.AreEqual(result[2, 1], matrix[2, 1]);
Assert.AreEqual(result[2, 2], matrix[2, 2]);
}
/// <summary>
/// Search for unassigned cell
/// </summary>
/// <param name="matrix">Matrix, where the cell is searched</param>
/// <exception cref="ArgumentNullException">
/// If we try to search in matrix, which is not initialized</exception>
/// <returns>The first unassigned cell or null if thre is no such</returns>
public static Cell FindEmptyCell(int[,] matrix)
{
if (matrix == null)
{
throw new ArgumentNullException(
"Invalid input! You cannot search in empty matrix.");
}
Cell cell = new Cell(0, 0);
for (int row = 0; row < matrix.GetLength(0); row++)
{
for (int column = 0; column < matrix.GetLength(0); column++)
{
if (matrix[row, column] == 0)
{
cell.Row = row;
cell.Column = column;
return cell;
}
}
}
return null;
}
/// <summary>
/// Check if next cell is usable
/// </summary>
/// <param name="matrix">2D array</param>
/// <param name="cell">struct Cell</param>
/// <param name="index">index of pattern array</param>
/// <returns>boolean value</returns>
private static bool IsNextCellUsable(int[,] matrix, Cell cell, int index)
{
var nextCell = new Cell()
{
X = cell.X + DirectionX[index],
Y = cell.Y + DirectionY[index]
};
return IsCellUsable(matrix, nextCell);
}
/// <summary>
/// Check if cell is usable, if it is inside
/// the matrix and if its equale to zero
/// </summary>
/// <param name="matrix">2D array</param>
/// <param name="cell">struct Cell </param>
/// <returns>boolean value</returns>
private static bool IsCellUsable(int[,] matrix, Cell cell)
{
bool isCellUsable = cell.X >= 0 && cell.X < matrix.GetLength(0) && cell.Y >= 0
&& cell.Y < matrix.GetLength(1) && matrix[cell.X, cell.Y] == 0;
return isCellUsable;
}
public void TestValidCell()
{
Cell cell = new Cell(3, 3);
Assert.AreEqual(3, cell.Row);
Assert.AreEqual(3, cell.Column);
}
public void TestCellNegativeRow()
{
Cell cell = new Cell(-3, 1);
}
/// <summary>
/// Find next possible direction to continue the traversal of a matrix
/// </summary>
/// <param name="matrix">Matrix to be traversed</param>
/// <param name="cell">Cell from which is searching direction</param>
/// <param name="direction">Current direction which could be changed</param>
/// <returns>Next direction to traverse the matrix</returns>
private static Direction FindDirection(int[,] matrix, Cell cell, Direction direction)
{
int size = matrix.GetLength(0);
bool isOuterRow = cell.Row + direction.X >= size || cell.Row + direction.X < 0;
bool isOuterColumn = cell.Column + direction.Y >= size || cell.Column + direction.Y < 0;
while (isOuterRow || isOuterColumn ||
matrix[cell.Row + direction.X, cell.Column + direction.Y] != 0)
{
direction = PossibleDirections.GetNextPossibleDirection(direction);
isOuterRow = cell.Row + direction.X >= size || cell.Row + direction.X < 0;
isOuterColumn = cell.Column + direction.Y >= size || cell.Column + direction.Y < 0;
}
return direction;
}
/// <summary>
/// Change all directions which are leading outside the matrix
/// </summary>
/// <param name="possibleDirections">Current possible directions</param>
/// <param name="matrix">Matrix to be traversed</param>
/// <param name="cell">Cell from which is searching direction</param>
private static void UpdatePossibleDirections(Direction[] possibleDirections, int[,] matrix, Cell cell)
{
for (int count = 0; count < possibleDirections.Length; count++)
{
int changedRow = cell.Row + possibleDirections[count].X;
if (changedRow >= matrix.GetLength(0) || changedRow < 0)
{
possibleDirections[count].X = 0;
}
int changedColumn = cell.Column + possibleDirections[count].Y;
if (changedColumn >= matrix.GetLength(0) || changedColumn < 0)
{
possibleDirections[count].Y = 0;
}
}
}
/// <summary>
/// Find if there is unassigned cell around current cell
/// </summary>
/// <param name="matrix">Matrix, where the cell is searched</param>
/// <param name="cell">Cell around which is searching</param>
/// <returns>Is or is not such cell</returns>
private static bool IsPath(int[,] matrix, Cell cell)
{
var isPath = false;
Direction[] possibleDirections = PossibleDirections.Generate();
UpdatePossibleDirections(possibleDirections, matrix, cell);
for (int count = 0; count < possibleDirections.Length; count++)
{
int changedRow = cell.Row + possibleDirections[count].X;
int changedColumn = cell.Column + possibleDirections[count].Y;
if (matrix[changedRow, changedColumn] == 0)
{
isPath = true;
}
}
return isPath;
}
/// <summary>
/// Check if there is avaliable
/// move, (empty cell)
/// </summary>
/// <param name="matrix">2D array</param>
/// <param name="cell">struct Cell</param>
/// <param name="index">index of pattern array</param>
/// <returns>boolean value</returns>
private static bool HasAvailableMove(int[,] matrix, Cell cell, int index)
{
foreach (var element in DirectionX)
{
index = (index + 1) % DirectionX.Length;
if (IsNextCellUsable(matrix, cell, index))
{
return true;
}
}
return false;
}
public void TestCellNegativeColumn()
{
Cell cell = new Cell(3, -1);
}
public void TestCellZero()
{
Cell cell = new Cell(0, 0);
Assert.AreEqual(0, cell.Row);
Assert.AreEqual(0, cell.Column);
}