public bool NiceLoop( ) //Depth-first Search
{
Prepare();
CeLKMan.PrepareCellLink(1 + 2); //Generate StrongLink,WeakLink
for (int szCtrl = 4; szCtrl < NiceLoopMax; szCtrl++)
{
foreach (var P0 in pBDL.Where(p => (p.No == 0))) //Origin Cell
{
foreach (var no in P0.FreeB.IEGet_BtoNo()) //Origin Number
{
foreach (var LKH in CeLKMan.IEGetRcNoType(P0.rc, no, 3)) //First Link
{
if (pAnMan.CheckTimeOut())
{
return(false);
}
var SolStack = new Stack <UCellLink>();
SolStack.Push(LKH);
Bit81 UsedCells = new Bit81(LKH.rc2); //Bit Representation of Used Cells
_NL_Search(LKH, LKH, SolStack, UsedCells, szCtrl - 1);
if (SolCode > 0)
{
return(true);
}
}
}
}
}
return(false);
}
private IEnumerable <Bit81[]> _GetXYChain(List <int> LKRec)
{
List <UCell> TBDbv = pBDL.FindAll(p => (p.FreeBC == 2)); //Extract BV_Cell(BV:bivalue).
foreach (var PS in TBDbv) //Choose one BV_Cell(=>PS)
{
int rcS = PS.rc;
foreach (var no in PS.FreeB.IEGet_BtoNo()) //Choose one digit(in PS)
{
int noB = (1 << no);
Bit81[] CRL = new Bit81[2];
CRL[0] = new Bit81(); //Position of the target digit to be concatenated
CRL[1] = new Bit81(); //Position of other digits to be connected
CRL[0].ID = rcS; CRL[1].ID = no;
Bit81 CnctdCs = ConnectedCells[rcS]; //Associated cells group of starting cell
Queue <int> rcQue = new Queue <int>();
int no0 = pBDL[rcS].FreeB.BitReset(no).BitToNum(); //The other digit of the starting cell
rcQue.Enqueue((no0 << 8) | rcS);
LKRec.Clear();
while (rcQue.Count > 0) //Extend the chain step by step
{
int rcX = rcQue.Dequeue();
int no1 = rcX >> 8, rc1 = rcX & 0xFF;
foreach (var LK in CeLKMan.IEGetRcNoType(rc1, no1, 1)) //strongLink connected with rc1, #no
{
int rc2 = LK.rc2;
if (pBDL[rc2].FreeBC != 2)
{
continue; //bivalue?
}
if (CRL[0].IsHit(rc2) || CRL[1].IsHit(rc2))
{
continue; //Different from colored cells?
}
//Exclude cells associated with the starting cell and having the same digit
if (CnctdCs.IsHit(rc2) && (pBDL[rc2].FreeB & noB) > 0)
{
continue;
}
int no2 = (pBDL[rc2].FreeB.BitReset(no1)).BitToNum(); //other digit
int nx = (no2 == no)? 0: 1;
CRL[nx].BPSet(rc2);
rcQue.Enqueue((no2 << 8) | rc2); //Put the next [Digit&Cell] in Queue
LKRec.Add((rc1 << 8 | rc2)); //Record Link
}
}
if (CRL[0].Count > 0 || CRL[1].Count > 0)
{
yield return(CRL);
}
}
}
yield break;
}
private IEnumerable <Bit81[]> _GetXChain(int no, List <int> LKRec)
{
Bit81 TBD = new Bit81(pBDL, (1 << no));
int rcS;
while ((rcS = TBD.FindFirstrc()) >= 0) //rcS:Set the origin cell.
{
TBD.BPReset(rcS); //Reset TBD to Processed.
//===== Repeatedly coloring processing. initialize =====
Bit81[] CRL = new Bit81[3]; //Coloring 2 groups(CRL[0] and CRL[1]).
CRL[0] = new Bit81(); CRL[1] = new Bit81(rcS); CRL[2] = new Bit81();
CRL[0].ID = rcS;
Queue <int> rcQue = new Queue <int>();
rcQue.Enqueue((rcS << 1) | 1); //(First StrongLink)
//===== Repeatedly coloring processing. start =====
LKRec.Clear(); //clear chain recorder.
bool firstLK = true;
while (rcQue.Count > 0)
{
int rcX = rcQue.Dequeue(); //recorded [cell and color]
int swF = 1 - (rcX & 1); //next color(inversion S-W)
int rc1 = (rcX >> 1); //next cell
foreach (var LKx in CeLKMan.IEGetRcNoType(rc1, no, (swF + 1))) //LKx:link connected to cell rc1
{
int rc2 = LKx.rc2; //anather cell of LKx
if ((CRL[0] | CRL[1]).IsHit(rc2))
{
continue; //already colored
}
CRL[swF].BPSet(rc2); //coloring
rcQue.Enqueue((rc2 << 1) | swF); //enqueue(next cell and color)
LKRec.Add(rc1 << 8 | rc2); //chain record
if (firstLK)
{
CRL[2].BPSet(rc2); //record colored cells from rcS(source cell)
}
}
firstLK = false;
}
if (CRL[1].Count > 0)
{
yield return(CRL);
}
//----- Repeatedly coloring processing. end -----
}
yield break;
}
private IEnumerable <Bit81[]> _Coloring(int no)
{
Bit81[] CRL = new Bit81[2];
CRL[0] = new Bit81(); CRL[1] = new Bit81();
Bit81 TBD = new Bit81(pBDL, (1 << no));
int rc1 = TBD.FindFirstrc();
while (rc1 >= 0)
{
Queue <int> rcQue = new Queue <int>();
rcQue.Enqueue(rc1 << 1);
CRL[0].BPSet(rc1);
TBD.BPReset(rc1);
while (rcQue.Count > 0)
{
rc1 = rcQue.Dequeue();
int kx = 1 - (rc1 & 1);
rc1 >>= 1;
TBD.BPReset(rc1);
foreach (var P in CeLKMan.IEGetRcNoType(rc1, no, 1))
{
int rc2 = P.rc2;
if (!(CRL[0] | CRL[1]).IsHit(rc2) && TBD.IsHit(rc2))
{
CRL[kx].BPSet(rc2); rcQue.Enqueue((rc2 << 1) | kx);
}
}
}
yield return(CRL);
if ((rc1 = TBD.FindFirstrc()) < 0)
{
yield break;
}
CRL = new Bit81[2];
CRL[0] = new Bit81(); CRL[1] = new Bit81();
}
yield break;
}