public ITruthTableRow Simplify(ITruthTableRow otherRow)
{
// Instead of creating a memory intense copy, we create a very simple row object
// that will only hold the truth values in each cell and a result.
int numberOfVariables = Cells.Length;
TruthTableRow simplifiedRow = new TruthTableRow(uniqueVariables, numberOfVariables);
simplifiedRow.Result = Result;
int numberOfDeferringValues = 0;
for (int i = 0; i < Cells.Length; i++)
{
if (Cells[i] != otherRow.Cells[i])
{
// Then we deal with a don't care variable, which we indicate by null.
simplifiedRow.Cells[i] = '*';
numberOfDeferringValues++;
if (numberOfDeferringValues > 1)
{
return(null);
}
}
else
{
simplifiedRow.Cells[i] = Cells[i];
}
}
return(simplifiedRow);
}
private List <ITruthTableRow> SimplifiyRowSet(List <ITruthTableRow> rowSet)
{
List <ITruthTableRow> simplifiedSet = new List <ITruthTableRow>();
for (int i = 0; i < rowSet.Count; i++)
{
for (int j = 0; j < rowSet.Count; j++)
{
// Skip comparing the same row.
if (j != i)
{
// Only attempt to simplify the row if they have the same result value.
if (rowSet[i].Result == rowSet[j].Result)
{
// Try to simplify the two by a method call.
// The method will return null if it was not succesfull
// or a new row if it was successful.
ITruthTableRow simplifiedRow = rowSet[i].Simplify(rowSet[j]);
if (simplifiedRow != null)
{
// Only assign is simplified to row i since that's the one under inspection.
rowSet[i].IsSimplified = true;
// Here we ensure that we only return unique rows,
// that means rows with all different symbols in the cells.
if (IsRowInSet(simplifiedRow, simplifiedSet) == false)
{
simplifiedSet.Add(simplifiedRow);
}
}
}
}
}
// We exhausted our option, meaning that row i was either simplified or not simplified,
// thus we have to add it to our set, ensuring one unique row is in it.
if (rowSet[i].IsSimplified == false)
{
if (IsRowInSet(rowSet[i], simplifiedSet) == false)
{
simplifiedSet.Add(rowSet[i]);
}
}
}
// If the set could not be simplified any further we can rewturn the original.
if (simplifiedSet.Count == 0)
{
return(rowSet);
}
// Else return the set of simplified rows.
return(simplifiedSet);
}
private bool IsRowInSet(ITruthTableRow row, List <ITruthTableRow> rowSet)
{
foreach (ITruthTableRow r in rowSet)
{
if (row.EqualTo(r))
{
return(true);
}
}
return(false);
}
public bool EqualTo(ITruthTableRow other)
{
if (Cells.Length != other.Cells.Length)
{
return(false);
}
for (int i = 0; i < Cells.Length; i++)
{
if (Cells[i] != other.Cells[i])
{
return(false);
}
}
return(true);
}
