public void Solve(uint value, SudokuRegion first, SudokuRegion second, SudokuRegionType otherType, SudokuState state, ICollection <IEvent> events)
{
buffer.Clear();
for (var index = 0; index < 9; index++)
{
var indexFirst = first[index];
var indexSecond = second[index];
var joinFirst = state[indexFirst] & value;
var joinSecond = state[indexSecond] & value;
if (joinFirst == 0)
{
if (joinSecond != 0)
{
return;
}
}
else
{
if (joinSecond == 0 || buffer.Count > 3)
{
return;
}
buffer.Add(indexFirst);
buffer.Add(indexSecond);
}
}
if (buffer.Count == 4)
{
var reducded = Fetch(
value,
first.Intersected.FirstOrDefault(r => r.RegionType == otherType),
state,
events);
reducded |= Fetch(
value,
second.Intersected.FirstOrDefault(r => r.RegionType == otherType),
state,
events);
if (reducded)
{
events.Add(ReducedOptions.Ctor <ReduceXWing>());
}
}
}
private void Solve(SudokuPuzzle puzzle, SudokuState state, ICollection <IEvent> events, SudokuRegionType type, SudokuRegionType otherType)
{
var pre = events.Count;
foreach (var first in puzzle.Regions.Where(r => r.RegionType == type))
{
foreach (var second in puzzle.Regions.Where(r => r.RegionType == otherType))
{
if (first != second)
{
foreach (var value in SudokuCell.Singles)
{
Solve(value, first, second, otherType, state, events);
if (events.Count != pre)
{
return;
}
}
}
}
}
}
/// <summary>Creates a Sudoku region.</summary>
public SudokuRegion(SudokuRegionType type)
{
RegionType = type;
Intersected = new SudokuRegions();
}
