public void RestoreMarkedHighlighted()
{
for (int i = 0; i < NumberOfRows; i++)
{
HighlightedRows[i] = false;
MarkedRows[i] = false;
}
for (int i = 0; i < NumberOfColls; i++)
{
HighlightedColls[i] = false;
MarkedColls[i] = false;
}
AssignedCells.Clear();
CrossedCells.Clear();
NewlyMarkedColls.Clear();
NewlyMarkedRows.Clear();
}
public void CoverZeroes()
{
DoAssignment();
MarkUnassignedRows();
while (true)
{
if (NewlyMarkedRows.Count() == 0)
{
break;
}
MarkCollsHavingZeroesInNewRows();
NewlyMarkedRows.Clear();
if (NewlyMarkedColls.Count() == 0)
{
break;
}
MarkRowsHavingAssignmentsInNewColls();
NewlyMarkedColls.Clear();
}
Highlight();
//internal functions
void DoAssignment()
{
for (int rowNum = 0; rowNum < NumberOfRows; rowNum++)
{
MatrixCell cell = FindZeroInARow(rowNum, 0);
if (cell != null)
{
AssignCell(cell);
// cross in a row
MatrixCell cellToCross = FindZeroInARow(rowNum, cell.Coll + 1);
while (cellToCross != null)
{
if (!IsCorssed(cellToCross))
{
CrossCell(cellToCross);
}
cellToCross = FindZeroInARow(rowNum, cellToCross.Coll + 1);
}
//Cross in a coll
cellToCross = FindZeroInAColl(cell.Coll, cell.Row + 1);
while (cellToCross != null)
{
if (!IsCorssed(cellToCross))
{
CrossCell(cellToCross);
}
cellToCross = FindZeroInAColl(cell.Coll, cellToCross.Row + 1);
}
}
}
void AssignCell(MatrixCell cell)
{
AssignedCells.Add(cell);
}
void CrossCell(MatrixCell cell)
{
CrossedCells.Add(cell);
}
bool IsCorssed(MatrixCell cell)
{
return(CrossedCells.Contains(cell));
}
bool IsAssigned(MatrixCell cell)
{
return(AssignedCells.Contains(cell));
}
MatrixCell FindZeroInARow(int rowNum, int startingFrom)
{
if (startingFrom >= NumberOfColls)
{
return(null);
}
for (int i = startingFrom; i < NumberOfColls; i++)
{
if (Matrix[rowNum, i] == 0)
{
MatrixCell cell = new MatrixCell(rowNum, i);
if (!IsCorssed(cell))
{
return(cell);
}
}
}
return(null);
}
MatrixCell FindZeroInAColl(int collNum, int startingFrom)
{
if (startingFrom >= NumberOfRows)
{
return(null);
}
for (int i = startingFrom; i < NumberOfRows; i++)
{
if (Matrix[i, collNum] == 0)
{
return(new MatrixCell(i, collNum));
}
}
return(null);
}
}
void MarkUnassignedRows()
{
IEnumerable <int> rowsToMark = Enumerable.Range(0, NumberOfRows).Except(AssignedCells.Select(c => c.Row).Distinct());
foreach (int rowNum in rowsToMark)
{
MarkRow(rowNum);
}
}
void MarkCollsHavingZeroesInNewRows()
{
foreach (int markedRow in NewlyMarkedRows)
{
for (int i = 0; i < NumberOfColls; i++)
{
if (Matrix[markedRow, i] == 0)
{
MarkColl(i);
}
}
}
}
void MarkRowsHavingAssignmentsInNewColls()
{
foreach (int markedColl in NewlyMarkedColls)
{
IEnumerable RowsToMark = AssignedCells.Where(c => c.Coll == markedColl).Select(c => c.Row);
foreach (int row in RowsToMark)
{
MarkRow(row);
}
}
}
void Highlight()
{
for (int i = 0; i < NumberOfRows; i++)
{
if (!MarkedRows[i])
{
HighlightedRows[i] = true;
}
}
for (int i = 0; i < NumberOfColls; i++)
{
if (MarkedColls[i])
{
HighlightedColls[i] = true;
}
}
}
void MarkRow(int rowNum)
{
if (!MarkedRows[rowNum])
{
MarkedRows[rowNum] = true;
NewlyMarkedRows.Add(rowNum);
}
}
void MarkColl(int collNum)
{
if (!MarkedColls[collNum])
{
MarkedColls[collNum] = true;
NewlyMarkedColls.Add(collNum);
}
}
}
