private UpdateResult RewindLastSummedGroup()
{
debugLog.Write("Cleaning out all groups.\n");
CellGroup groupToMove = cellGroupsWithSums.Pop();
CleanOutAllCellValues();
groupToMove.RestoreAllData();
cellGroupsWithoutSums.Push(groupToMove);
return(UpdateResult.repaired);
}
/*************************************************************************************
* FindSolutionsForCells
*------------------------------------------------------------------------------------
* This method takes a cellToTry from the matrix, and examines the cellToTry's corresponding
* parent groups (i.e. the collumn and row to which the cellToTry belongs.) One of
* the parent groups is selected to be maximized, and the other is minimized. The
* digit for the cellToTry is then the only possible digit at the interesection of the two
*
* Outstanding problems:
* A sum can be set for a group that is impossible to achieve because possible values
* for copyOfUnsolvedCellList have not been checked.
*
*************************************************************************************/
private UpdateResult FindSolutionsForCells()
{
debugLog.Write("\n________________________________\n\n");
UpdateResult setSumResult = UpdateResult.unchanged;
UpdateResult solvePuzzleResult = UpdateResult.unchanged;
if (cellGroupsWithoutSums.Count != 0)
{
CellGroup groupToSolve = cellGroupsWithoutSums.Peek();
try
{
setSumResult = groupToSolve.SetTheSum();
// write a new method that checks for groups that could swapcells. If a pair is found,
// throw an IllegalSumException2.
MoveNextGroupToSummedQueue();
}
catch (IllegalSumException2 exception)
{
debugLog.Write("There was a problem finding a sum. Restoring group.\n");
debugLog.Write(exception.Message);
setSumResult = groupToSolve.RestoreAllData();
CleanOutAllCellValues();
}
// The following has been removed to a higher level. now we just let it go,
// and recreate the puzzle from scratch.
//catch (UnsolvableGroupException2 exception)
//{
// debugLog.Write("The current group cannot be solved. Reverting last group.\n");
// debugLog.Write(exception.Message);
// setSumResult = groupToSolve.RestoreAllData(); // No... Something more is needed. Complete reset.
// setSumResult = RewindLastSummedGroup();
//}
debugLog.Write("=================>SetTheSum returned success:" + setSumResult + "\n");
solvePuzzleResult = SolvePuzzle();
}
else
{
solvePuzzleResult = SolvePuzzle();
debugLog.Write("=================>SolvePuzzle returned success:" + solvePuzzleResult + "\n");
foreach (CellGroup group in cellGroupsWithSums)
{
if (group.CannotBeSolved())
{
debugLog.Write(" SolvePuzzle found an unsolvable group.\n");
debugLog.Write(" I'm not going to raise an error, I'll just handle it here.\n");
RewindLastSummedGroup();
return(UpdateResult.repaired);
}
}
}
if ((setSumResult == UpdateResult.repaired) ||
(solvePuzzleResult == UpdateResult.repaired))
{
return(UpdateResult.repaired);
}
if ((setSumResult == UpdateResult.changed) ||
(solvePuzzleResult == UpdateResult.changed))
{
return(UpdateResult.changed);
}
return(UpdateResult.unchanged);
}
