internal override List <int> GetPencilmarkList(NakedHiddenFinder hiddenFinder)
{
List <int> returnValue = hiddenFinder.ActionBits
.BitMerge()
.ListOfBits();
return(returnValue);
}
internal override List <int> GetLocationList(NakedHiddenFinder hiddenFinder)
{
int mask = 0;
hiddenFinder.ActionIndexes
.Select(i => hiddenFinder.MapBits[i])
.ToList()
.ForEach(pmsign => mask |= pmsign);
List <int> returnValue = mask.ListOfBits();
return(returnValue);
}
internal override List <int> GetLocationList(NakedHiddenFinder hiddenFinder)
{
return(hiddenFinder.ActionIndexes);
}
internal override List <int> GetPencilmarkList(NakedHiddenFinder hiddenFinder)
{
return(hiddenFinder.ActionIndexes);
}
public override bool FindPattern(GameBoard board)
{
// The algorithm is the same for finding naked or hidden values. For naked:
// an array of integers where each integer is a set of bits for the pencilmarks.
// (e.g. 01 0110 0010 == 0x162 which mean pencilmark 1, 5, 6, and 8 are set. The
// LSB is position 0), and the index in the array is a cell position in the line.
// For Hidden: Swap the meaning: The bits are the positions in the line and the
// index is the pencilmark.
// Start from the beginning in the array. Its content is a cumulative mask.
// If the cumulative mask has more than the goal bits, it is thrown away and the
// next one is considered. If N bits are found in a mask using N entries in the
// array, then there are N of N which is what is being searched for. Once found,
// a "final approval method" is invoked to check if the set is good. The approval
// is determined to be good if there are pencilmarks to turn off. (for naked, in
// other positions in the line. for hidden: more pencilmarks in the same cells
// (other than the N found (e.g. found 1,2,3 but cell also has 2,7 which can be
// turned off. Since there is a large number of combinations the best approach
// to try promising ones and discard useless ones quickly is to use recursion.
// Since a board has a small number of cells (9 or so) the recursion depth is not
// an issue.
Board = board;
for (int coord = Coord.ROWS; coord <= Coord.SECTIONS; coord++)
{
List <List <Cell> > allLines = Board.GetAllLines(coord);
foreach (List <Cell> line in allLines)
{
var hiddenFinder = new NakedHiddenFinder();
int dim = line.Count + 1;
hiddenFinder.MapBits = CreateMapBits(line);
hiddenFinder.MapLength = hiddenFinder.MapBits.Count;
// Step 2: Search for N of N values
int maxGoal = hiddenFinder.MapBits.Count(t => t != 0);
if (maxGoal == 0)
{
continue;
}
int goal = 1;
for (; goal < maxGoal; goal++)
{
if (hiddenFinder.Search(goal))
{
break;
}
}
// Finally set the information as related to cells, and information
if (goal == maxGoal)
{
continue;
}
LineCoordinate = coord;
int indexLine = line[0].GetCoordinate(LineCoordinate);
List <int> locationList = GetLocationList(hiddenFinder);
patternCells = locationList.Select(i => line[i]).ToList();
PencilmarkList = GetPencilmarkList(hiddenFinder);
Solution = new SolveInfo();
int pmMask = GetPencilmarkMask();
int patternPMs = 0;
patternCells.ForEach(cell => patternPMs |= cell.PMSignature);
locationList
.Select(loc => line[loc])
.ToList()
.ForEach(cell => Solution.AddAction(cell, CellRole.Pattern,
GetPmFindings(cell, patternPMs, PMRole.Pattern)));
List <int> solutionPMs = pmMask.ListOfBits();
CalculateAffectedCells(line);
affectedCells.ForEach(affCell =>
Solution.AddAction(affCell, AffectedCellRole,
GetPmFindings(affCell,
new int[] { pmMask, patternPMs },
new PMRole[] { PMRole.Remove, PMRole.Pattern })));
line
.Except(patternCells)
.Except(affectedCells)
.ToList()
.ForEach(cell => Solution.AddAction(cell, CellRole.InvolvedLine));
CreateRuleInformation();
return(true);
}
}
return(false);
}
internal abstract List <int> GetPencilmarkList(NakedHiddenFinder hiddenFinder);
internal abstract List <int> GetLocationList(NakedHiddenFinder hiddenFinder);
private bool MakesUniqueRectangle(List <Cell> firstTwo)
{
int keySignature = firstTwo[0].PMSignature;
string csvAffected, csvPattern, csvHalf2;
int commonCoord;
int lineIndex;
if ((lineIndex = firstTwo[0].RowIndex) == firstTwo[1].RowIndex)
{
commonCoord = Coord.ROW;
}
else if ((lineIndex = firstTwo[0].ColIndex) == firstTwo[1].ColIndex)
{
commonCoord = Coord.COL;
}
else
{
return(false);
}
int diffCoord = 1 - commonCoord;
List <int> cellIndexes = firstTwo
.Select(cell => cell.GetCoordinate(diffCoord))
.ToList();
List <List <Cell> > workLine = (commonCoord == Coord.ROW) ? allRows : allColumns;
List <List <Cell> > secondHalfLineCandidates = workLine
.Where(line => line[0].GetCoordinate(commonCoord) != lineIndex &&
(line[cellIndexes[0]].PMSignature & keySignature) == keySignature &&
(line[cellIndexes[1]].PMSignature & keySignature) == keySignature)
.ToList();
foreach (List <Cell> half2Line in secondHalfLineCandidates)
{
int half2PencilmarkCount = 0;
List <Cell> half2 = new List <Cell> {
half2Line[cellIndexes[0]], half2Line[cellIndexes[1]]
};
if (firstTwo.Union(half2)
.Select(cell => cell.GetCoordinate(Coord.SECTION))
.Distinct()
.Count() != 2)
{
continue;
}
List <Cell> half2ManyPMs = half2.Where(cell => cell.PencilMarkCount > 2).ToList();
half2.ForEach(cell => half2PencilmarkCount += cell.PencilMarkCount);
int pmOtherMask;
// Unique Rectangle - Type 1
// 3 cells in the rectangle have 2 options, and the 4th cell has more.
// In the 4th cell, the 2 common options should be turned off.
if (half2ManyPMs.Count == 1)
{
Solution = new SolveInfo();
Cell solutionCell = half2ManyPMs[0];
patternCells = new List <Cell>(firstTwo);
patternCells.AddRange(half2.Except(half2ManyPMs).ToList());
patternCells.ForEach(cell => Solution.AddAction(cell, CellRole.Pattern,
GetPmFindings(cell, keySignature, PMRole.Pattern)));
affectedCells = half2ManyPMs;
Solution.AddAction(solutionCell, CellRole.Pattern,
GetPmFindings(solutionCell, keySignature, PMRole.Remove));
patternCells.Add(solutionCell); // to include in description
csvPattern = CellsInCsvFormat(patternCells);
csvAffected = CellsInCsvFormat(affectedCells);
string csvValues = PMsInCsvFormat(keySignature.ListOfBits());
string csvSolutionCell = CellsInCsvFormat(solutionCell);
Solution.Description = $"Unique Rectangle - Type 1 : Cell {csvAffected} cannot " +
$"have values {csvValues}. Otherwise a deadly pattern would form in cells {csvPattern}. " +
$"Therefore these values can be ruled out for that cell.";
return(true);
}
// Possible case of Unique Rectangle - Type 2
// 2 cells have 3 pencilmarks set (the same 3 for both), so one of the
// 2 cells must be the 3rd value. No other cells in the line (and section)
// can hold that value.
if (half2PencilmarkCount == 6 &&
half2[0].PMSignature == half2[1].PMSignature)
{
Solution = new SolveInfo();
int mask = half2[0].PMSignature ^ keySignature;
affectedCells = half2Line.Except(half2)
.Where(cell => (cell.PMSignature & mask) != 0)
.ToList();
if (affectedCells.Count != 0)
{
List <Cell> affectedInGroup = Board
.GetLine(Coord.SECTION, half2[0].GetCoordinate(Coord.SECTION))
.Except(half2)
.Where(cell => (cell.PMSignature & mask) != 0)
.ToList();
affectedCells.AddRange(affectedInGroup);
patternCells = new List <Cell>(firstTwo);
patternCells.AddRange(half2);
affectedCells
.ForEach(cell => Solution.AddAction(cell, CellRole.Affected,
GetPmFindings(cell, mask, PMRole.Remove)));
Board.GetLine(commonCoord, lineIndex)
.Except(affectedCells)
.ToList()
.ForEach(cell => Solution.AddAction(cell, CellRole.InvolvedLine));
int iValue = mask.ListOfBits()[0];
csvPattern = CellsInCsvFormat(patternCells);
csvAffected = CellsInCsvFormat(affectedCells);
csvHalf2 = CellsInCsvFormat(half2);
Solution.Description = $"Unique Rectangle - Type 2: Value {iValue} has to " +
$"be present in one of cells {csvHalf2} to avoid a deadly pattern (where the puzzle " +
$"would have 2 solutions). Therefore, value 2 cannot be present in any of " +
$"cells {csvAffected}.";
return(true);
}
}
// Possible case of Unique Rectangle - Type 3
// 2 cells have 3 or 4 pencilmarks. The extra pencilmarks are treated as if
// they were all in a single cell, and a naked pattern is searched for in the line
// using these extra values.
// Example: 4 cells have pencilmarks 3,9 - 3,9 - 1,5,3,9 - 1,5,3,9 . The extra
// values (1 and 5) are treated as being in a single cell, and a naked pattern is
// searched for. If 2 other cells have (1,4) and (4,5), then the 2 cells and the
// virtual cell form a naked cell group of size 3 with values 1, 4, 5, and the naked
// rule is applied accordingly on the line.
if (half2PencilmarkCount >= 6 && half2PencilmarkCount <= 8)
{
do
{
int pmsVirtualCell = 0;
half2.ForEach(cell => pmsVirtualCell |= cell.PMSignature);
pmsVirtualCell ^= firstTwo[0].PMSignature;
if (pmsVirtualCell.NumberOfBitsSet() != 2)
{
continue;
}
// clear one of the virtual cells completely
List <Cell> virtualLine = half2Line.Select(t => t.Clone()).ToList();
// change the pencilmarks in the other cell to match the virtual definition
virtualLine[cellIndexes[0]].SetValue(0); // clear pencilmarks
virtualLine[cellIndexes[1]].SetValue(0);
virtualLine[cellIndexes[1]].SetMultiplePencilMarks(pmsVirtualCell);
// Now perform a search for a naked rule set
NakedHiddenFinder finder = new NakedHiddenFinder();
finder.MapBits = NakedValuesRule.CreateMapBitsFromLine(virtualLine);
finder.MapLength = virtualLine.Count;
if (!finder.Search(2 /*goal*/) && !finder.Search(3 /*goal*/))
{
continue;
}
int pmsVirtualGroup = finder.ActionIndexes
.Select(i => half2Line[i].PMSignature)
.ToList()
.BitMerge();
affectedCells = new List <Cell>();
Solution = new SolveInfo();
pmOtherMask = finder.ActionBits.BitMerge();
affectedCells = half2Line
.Except(finder.ActionIndexes.Select(i => half2Line[i]).ToList())
.Except(half2)
.Where(cell => (cell.PMSignature & pmOtherMask) != 0)
.ToList();
affectedCells.ForEach(cell => Solution.AddAction(cell, CellRole.Affected,
GetPmFindings(cell, pmOtherMask, PMRole.Remove)));
int deadlySignature = firstTwo[0].PMSignature;
firstTwo.ForEach(cell => Solution.AddAction(cell, CellRole.Pattern,
GetPmFindings(cell, deadlySignature, PMRole.Pattern)));
half2.ForEach(cell => Solution.AddAction(cell, CellRole.Pattern,
GetPmFindings(cell,
new int[] { deadlySignature, pmsVirtualCell },
new PMRole[] { PMRole.Pattern, PMRole.ChainColor1 })));
List <Cell> virtualGroup = finder.ActionIndexes
.Except(cellIndexes)
.Select(i => half2Line[i])
.ToList();
virtualGroup.ForEach(cell => Solution.AddAction(cell, CellRole.InvolvedLine,
GetPmFindings(cell, pmsVirtualGroup, PMRole.ChainColor1)));
List <Cell> deadlyCells = firstTwo.Union(half2).ToList();
patternCells = deadlyCells
.Union(finder.ActionIndexes.Select(indexCell => half2Line[indexCell]))
.ToList();
List <Cell> line = Board.GetLine(commonCoord, half2[0].GetCoordinate(commonCoord));
line
.Except(affectedCells)
.Except(half2)
.Except(virtualGroup)
.ToList()
.ForEach(cell => Solution.AddAction(cell, CellRole.InvolvedLine));
csvAffected = CellsInCsvFormat(affectedCells);
csvPattern = CellsInCsvFormat(patternCells);
csvHalf2 = CellsInCsvFormat(half2);
string csvDeadly = CellsInCsvFormat(deadlyCells);
string csvValues = PMsInCsvFormat(pmOtherMask.ListOfBits());
string csvPmVirtual = PMsInCsvFormat(pmsVirtualCell.ListOfBits());
string commonCoordName = (commonCoord == Coord.ROW) ? "row" : "column";
string csvNakedGroup = PMsInCsvFormat((pmOtherMask | pmsVirtualCell).ListOfBits());
Solution.Description = string.Format("Unique Rectangle Type 3: Cells {0} form a single " +
"virtual cell with pencilmarks {1}. A deadly pattern in cells {2} cannot take " +
"place. One of values {1} has to be present in cells {0} (Naked rule applied " +
"using virtual cell for pencilmarks {3}) . Options {5} can be removed from cells " +
"{6}.", csvHalf2, csvPmVirtual, csvDeadly, csvNakedGroup, commonCoordName,
csvValues, csvAffected);
return(true);
}while (false); // builds a common exit point
}
// Last case: Unique Rectangle - Type 4
// 2 cells have many more pencilmarks set. One of the extra values HAS to be
// the solution for one of the cells. Then the 4th cell cannot hold the other
// value (of the deadly rectangle) or else a deadly pattern would form
if (half2PencilmarkCount < 6)
{
continue;
}
List <Cell> analysisCells = half2Line
.Except(half2)
.ToList();
List <int> pmAnalysis = keySignature.ListOfBits();
int pmWork = pmAnalysis.FirstOrDefault(pm => analysisCells.FirstOrDefault(
cell => cell.IsPencilmarkSet(pm)) == null);
if (pmWork == 0)
{
continue;
}
Solution = new SolveInfo();
int pmOther = pmAnalysis.FirstOrDefault(t => t != pmWork);
affectedCells = half2.Where(cell => cell.IsPencilmarkSet(pmOther)).ToList();
patternCells = firstTwo.Union(half2).Except(affectedCells).ToList();
pmOtherMask = 1 << pmOther;
int pmWorkMask = 1 << pmWork;
affectedCells.ForEach(cell => Solution.AddAction(cell, CellRole.Pattern,
GetPmFindings(cell,
new int[] { pmOtherMask, pmWorkMask }, new PMRole[] { PMRole.Remove, PMRole.Pattern })));
patternCells.ForEach(cell => Solution.AddAction(cell, CellRole.Pattern,
GetPmFindings(cell, pmWorkMask | pmOtherMask, PMRole.Pattern)));
lineIndex = half2[0].GetCoordinate(commonCoord);
Board.GetLine(commonCoord, lineIndex)
.Except(affectedCells)
.ToList()
.ForEach(cell => Solution.AddAction(cell, CellRole.InvolvedLine));
patternCells.AddRange(affectedCells); // to build description
csvAffected = CellsInCsvFormat(affectedCells);
csvPattern = CellsInCsvFormat(patternCells);
csvHalf2 = CellsInCsvFormat(half2);
string lineName = (commonCoord == Coord.ROW) ? "row" : "column";
Solution.Description = string.Format("Unique Rectangle - Type 4: Either one of cells {0}" +
"must have value {1}. If the other cell of the two had value {2}, the 4 cells {3} " +
"would form a deadly pattern. Since this cannot happen, cell {4} cannot hold value {2}.",
csvHalf2, pmWork, pmOther, csvPattern, csvAffected, lineName);
return(true);
}
return(false);
}
