void CreateNearestNeighborCandidateSet(int K)
{
Node *From, *To;
int i;
if (TraceLevel >= 2)
printff("Creating nearest neighbor candidate set ... ");
KDTree = BuildKDTree(1);
assert(XMin =
(double *) malloc((1 + DimensionSaved) * sizeof(double)));
assert(XMax =
(double *) malloc((1 + DimensionSaved) * sizeof(double)));
assert(YMin =
(double *) malloc((1 + DimensionSaved) * sizeof(double)));
assert(YMax =
(double *) malloc((1 + DimensionSaved) * sizeof(double)));
if (CoordType == THREED_COORDS) {
assert(ZMin =
(double *) malloc((1 + DimensionSaved) * sizeof(double)));
assert(ZMax =
(double *) malloc((1 + DimensionSaved) * sizeof(double)));
}
ComputeBounds(0, Dimension - 1);
Contains = CoordType == THREED_COORDS ? Contains3D : Contains2D;
BoxOverlaps =
CoordType == THREED_COORDS ? BoxOverlaps3D : BoxOverlaps2D;
assert(CandidateSet =
(Candidate *) malloc((K + 1) * sizeof(Candidate)));
From = FirstNode;
do {
NearestQuadrantNeighbors(From, 0, K);
for (i = 0; i < Candidates; i++) {
To = CandidateSet[i].To;
AddCandidate(From, To, D(From, To), 1);
}
} while ((From = From->Suc) != FirstNode);
free(CandidateSet);
free(KDTree);
free(XMin);
free(XMax);
free(YMin);
free(YMax);
if (CoordType == THREED_COORDS) {
free(ZMin);
free(ZMax);
}
if (Level == 0 && (WeightType == GEOM || WeightType == GEOM_MEEUS)) {
Candidate **SavedCandidateSet;
assert(SavedCandidateSet =
(Candidate **) malloc((1 + DimensionSaved) *
sizeof(Candidate *)));
if (TraceLevel >= 2)
printff("done\n");
/* Transform longitude (180 and -180 map to 0) */
From = FirstNode;
do {
SavedCandidateSet[From->Id] = From->CandidateSet;
From->CandidateSet = 0;
From->Yc = From->Y;
From->Y += From->Y > 0 ? -180 : 180;
} while ((From = From->Suc) != FirstNode);
Level++;
CreateNearestNeighborCandidateSet(K);
Level--;
From = FirstNode;
do
From->Y = From->Yc;
while ((From = From->Suc) != FirstNode);
do {
Candidate *QCandidateSet = From->CandidateSet;
Candidate *NFrom;
From->CandidateSet = SavedCandidateSet[From->Id];
for (NFrom = QCandidateSet; (To = NFrom->To); NFrom++)
AddCandidate(From, To, NFrom->Cost, NFrom->Alpha);
free(QCandidateSet);
} while ((From = From->Suc) != FirstNode);
free(SavedCandidateSet);
}
if (Level == 0) {
ResetCandidateSet();
AddTourCandidates();
if (CandidateSetSymmetric)
SymmetrizeCandidateSet();
if (TraceLevel >= 2)
printff("done\n");
}
}
void LKH::LKHAlg::CreateCandidateSet()
{
GainType Cost, MaxAlpha, A;
Node *Na;
int CandidatesRead = 0, i;
double EntryTime = GetTime();
Norm = 9999;
if (C == &LKH::LKHAlg::C_EXPLICIT) {
Na = FirstNode;
do {
for (i = 1; i < Na->Id; i++)
Na->C[i] *= Precision;
}
while ((Na = Na->Suc) != FirstNode);
}
if (Distance == &LKH::LKHAlg::Distance_1 ||
(MaxTrials == 0 &&
(FirstNode->InitialSuc || InitialTourAlgorithm == SIERPINSKI ||
InitialTourAlgorithm == MOORE))) {
ReadCandidates(MaxCandidates);
AddTourCandidates();
if (ProblemType == HCP || ProblemType == HPP)
Ascent();
goto End_CreateCandidateSet;
}
if (TraceLevel >= 2)
printff("Creating candidates ...\n");
if (MaxCandidates > 0 &&
(CandidateSetType == QUADRANT || CandidateSetType == NN)) {
ReadPenalties();
if (!(CandidatesRead = ReadCandidates(MaxCandidates)) &&
MaxCandidates > 0) {
if (CandidateSetType == QUADRANT)
CreateQuadrantCandidateSet(MaxCandidates);
else if (CandidateSetType == NN)
CreateNearestNeighborCandidateSet(MaxCandidates);
} else {
AddTourCandidates();
if (CandidateSetSymmetric)
SymmetrizeCandidateSet();
}
goto End_CreateCandidateSet;
}
if (!ReadPenalties()) {
/* No PiFile specified or available */
Na = FirstNode;
do
Na->Pi = 0;
while ((Na = Na->Suc) != FirstNode);
CandidatesRead = ReadCandidates(MaxCandidates);
Cost = Ascent();
if (Subgradient && SubproblemSize == 0) {
WritePenalties();
PiFile = 0;
}
} else if ((CandidatesRead = ReadCandidates(MaxCandidates)) ||
MaxCandidates == 0) {
AddTourCandidates();
if (CandidateSetSymmetric)
SymmetrizeCandidateSet();
goto End_CreateCandidateSet;
} else {
if (CandidateSetType != DELAUNAY && MaxCandidates > 0) {
if (TraceLevel >= 2)
printff("Computing lower bound ... ");
Cost = Minimum1TreeCost(0);
if (TraceLevel >= 2)
printff("done\n");
} else {
CreateDelaunayCandidateSet();
Na = FirstNode;
do {
Na->BestPi = Na->Pi;
Na->Pi = 0;
}
while ((Na = Na->Suc) != FirstNode);
if (TraceLevel >= 2)
printff("Computing lower bound ... ");
Cost = Minimum1TreeCost(1);
if (TraceLevel >= 2)
printff("done\n");
Na = FirstNode;
do {
Na->Pi = Na->BestPi;
Cost -= 2 * Na->Pi;
}
while ((Na = Na->Suc) != FirstNode);
}
}
LowerBound = (double) Cost / Precision;
if (TraceLevel >= 1) {
/* printff("Lower bound = %0.1f", LowerBound);
if (Optimum != MINUS_INFINITY && Optimum != 0)
printff(", Gap = %0.2f%%",
100.0 * (Optimum - LowerBound) / Optimum);
if (!PiFile)
printff(", Ascent time = %0.2f sec.",
fabs(GetTime() - EntryTime));
printff("\n"); */
if (Optimum != MINUS_INFINITY && Optimum != 0)
m_Gap=100.0 * (Optimum - LowerBound) / Optimum;
if (!PiFile)
m_AscentTime=fabs(GetTime() - EntryTime);
}
MaxAlpha = (GainType) fabs(Excess * Cost);
if ((A = Optimum * Precision - Cost) > 0 && A < MaxAlpha)
MaxAlpha = A;
if (CandidateSetType == DELAUNAY || MaxCandidates == 0)
OrderCandidateSet(MaxCandidates, MaxAlpha, CandidateSetSymmetric);
else
GenerateCandidates(MaxCandidates, MaxAlpha, CandidateSetSymmetric);
End_CreateCandidateSet:
if (ExtraCandidates > 0) {
AddExtraCandidates(ExtraCandidates,
ExtraCandidateSetType,
ExtraCandidateSetSymmetric);
AddTourCandidates();
}
ResetCandidateSet();
Na = FirstNode;
do {
if (!Na->CandidateSet || !Na->CandidateSet[0].To) {
if (MaxCandidates == 0)
eprintf("MAX_CANDIDATES = 0: Node %d has no candidates",
Na->Id);
else
eprintf("Node %d has no candidates", Na->Id);
}
}
while ((Na = Na->Suc) != FirstNode);
if (!CandidatesRead && SubproblemSize == 0)
WriteCandidates();
if (C == &LKH::LKHAlg::C_EXPLICIT) {
Na = FirstNode;
do
for (i = 1; i < Na->Id; i++)
Na->C[i] += Na->Pi + NodeSet[i].Pi;
while ((Na = Na->Suc) != FirstNode);
}
if (TraceLevel >= 1) {
CandidateReport();
// printff("Preprocessing time = %0.2f sec.\n",
// fabs(GetTime() - EntryTime));
}
}
