private List <List <CellState> > FindSolution(WorkingCopy assignments, Nonogram n, List <List <List <CellState> > > cellStates)
{
int nullIndex = assignments.AssignedRows.FindIndex(x => x == null);
if (nullIndex < 0)
{
if (!containsErrors(assignments, n))
{
return(assignments.AssignedRows);
}
else
{
return(null);
}
}
var rowVariants = cellStates[nullIndex];
var workingCopy = assignments.Clone() as WorkingCopy;
foreach (var value in rowVariants)
{
workingCopy.AssignedRows[nullIndex] = value;
if (containsErrors(assignments, n))
{
continue;
}
var resultsSearch = FindSolution(workingCopy, n, cellStates);
if (resultsSearch != null)
{
return(resultsSearch);
}
}
return(null);
}