protected override void OperateOn(SudokuModel model)
{
for (var iType = 0; iType < 3; ++iType) {
var type = (RegionType)iType;
for (var i = 0; i < model.Size; ++i) {
var region = new Region(type, i);
var tuple = new Tuple<SudokuModel, Region>(model, region);
if (GetCheckedIteration(tuple) < model.GetLastChangedIterRegion(type, i)) {
_checkedIteration[tuple] = model.ChangeCount;
foreach (var unsolved in model.GetUnsolvedValues(type, i)) {
var timesFound = 0;
Cell? foundAt = null;
foreach (var cell in model.GetCells(type, i)) {
if ((model.GetPossibilitySetCell(cell.Column, cell.Row) & (1 << unsolved)) != 0) {
++timesFound;
foundAt = cell;
if (timesFound > 1) {
break;
}
}
}
if (timesFound == 1) {
if (foundAt != null) {
model.SetValueOptimized(foundAt.Value.Column, foundAt.Value.Row, unsolved, type, i);
}
}
}
}
}
}
}
