private static SearchMove[] GetMoves(IJobShopLayer origin, ITabooList tabooList, Random random)
{
if (origin.GetConnectionsCost() > .5 * origin.GetTotalCost())
{
return(origin.GetMoves(
connectionFix: true,
connectionImprovement: true,
criticalArcsBased: tabooList.Any(),
routeSwapBased: false,
routeSwapWithHeuristicInsertion: false, //true, //!tabooList.Any(),
jobReinsertion: false,
routePenaltyImprovement: false)
.Shuffle(random)
.Select(m => new SearchMove(m))
.ToArray());
}
if (origin.GetDelayCost() > origin.GetRoutingCost())
{
bool changeRoute = !tabooList.Any() || random.NextDouble() < .3;
return(origin
.GetMoves(
connectionFix: true,
connectionImprovement: true,
criticalArcsBased: true,
routeSwapBased: changeRoute,
routeSwapWithHeuristicInsertion: changeRoute, //true, //!tabooList.Any(),
jobReinsertion: changeRoute,
routePenaltyImprovement: false)
.Shuffle(random)
.Select(m => new SearchMove(m))
.ToArray());
}
else
{
return(origin
.GetMoves(false, false, false, false, false, false, routePenaltyImprovement: true)
.Shuffle(random).Select(m => new SearchMove(m)).ToArray());
}
}
private static IJobShopLayer Step(
int iteration,
IJobShopLayer origin,
double bestCost,
ITabooList tabooList,
Random random,
double moveImmediatelyImprovementRate = 0.00001, // improvement >= 0.001% -> move to the next solution immediately
int minArcsToCheckCount = 1,
bool verbose = true)
{
TimesGraphIntegrity.DoCheck(origin.RoutingLayer.ClosureLayer.SequencingLayer.GraphLayer);
var moves = GetMoves(origin, tabooList, random);
if (moves.Length == 0)
{
throw new NoMoves();
}
if (verbose)
{
Console.WriteLine($"Inspecting {moves.Length} moves.");
}
//TabooType[] tabooTypes = new TabooType[moves.Length]; // init all to 'unknown'
if (tabooList.Any())
{
for (int i = 0; i < moves.Length; i++)
{
if (tabooList.IsAprioriTaboo(moves[i].ActualMove))
{
moves[i].TabooType = TabooType.AprioriTaboo;
}
}
}
double originCost = origin.GetTotalCost();
//double[] resultCosts = Enumerable.Repeat(double.MaxValue, moves.Length).ToArray();
// Try the moves.
for (int i = 0; i < moves.Length; i++)
{
if (moves[i].TabooType == TabooType.AprioriTaboo)
{
if (verbose)
{
Console.Write(ShortToString(moves[i].TabooType) + " ");
}
continue;
}
// Clone & execute.
var clone = origin.Clone();
clone.ExecuteMove(moves[i].ActualMove);
moves[i].Cost = clone.GetTotalCost();
// Never trust yourself
Assert(SingleThreadSearchChecks, clone.GetHashCode() != origin.GetHashCode() || !clone.Equals(origin));
// decide if the move is taboo
if (!tabooList.Any())
{
moves[i].TabooType = TabooType.NotTaboo;
}
else if (moves[i].Cost < 0.9999 * bestCost)
{
moves[i].TabooType = TabooType.Ascension;
}
else if (tabooList.IsAposterioriTaboo(clone))
{
moves[i].TabooType = TabooType.AposterioriTaboo;
}
else
{
moves[i].TabooType = TabooType.NotTaboo;
}
if (verbose)
{
Console.Write(
ShortToString(moves[i].TabooType)
+ (moves[i].Cost < 0.9999 * originCost? "^" : "")
+ " ");
}
// break, if the improvement is large enough (&& not taboo).
double improvementRate = (bestCost - moves[i].Cost) / bestCost;
if (i > minArcsToCheckCount &&
improvementRate > moveImmediatelyImprovementRate &&
(moves[i].TabooType == TabooType.Ascension || moves[i].TabooType == TabooType.NotTaboo))
{
break;
}
}
if ((iteration % 10) == 0)
{
//Console.WriteLine("hello...");
}
// Find the move to return.
int candidateIndex = -1;
Move candidate = null;
for (int i = 0; i < moves.Length; i++)
{
var move = moves[i];
var taboo = moves[i].TabooType;
if ((candidateIndex == -1 || moves[i].Cost < moves[candidateIndex].Cost) &&
taboo != TabooType.AposterioriTaboo &&
taboo != TabooType.AprioriTaboo)
{
candidateIndex = i;
candidate = move.ActualMove;
}
}
Assert(SingleThreadSearchChecks, candidate != null);
if (candidate == null)
{
Console.WriteLine("all moves taboo!");
double minCost = moves.Select(m => m.Cost).Min();
candidateIndex = Enumerable.Range(0, moves.Length).First(i => (moves[i].Cost == minCost));
candidate = moves[candidateIndex].ActualMove;
}
if (moves[candidateIndex].Cost > 0.9999 * bestCost)
{
tabooList.ProhibitUndoOfMove(origin, candidate);
Assert(SingleThreadSearchChecks, tabooList.IsAprioriTaboo(candidate) ||
tabooList.IsAposterioriTaboo(origin),
"When adding elements to the taboo-list, the original solution (before executing the move) must be taboo.");
if (SingleThreadSearchChecks.On &&
(candidate.Type == MoveType.RemoveCriticalArcLeftClosure ||
candidate.Type == MoveType.RemoveCriticalArcRightClosure))
{
Assert(SingleThreadSearchChecks, origin.TransitiveArcExist(candidate.CriticalArc));
var target = origin.Clone();
target.ExecuteMove(candidate);
Assert(SingleThreadSearchChecks, !target.TransitiveArcExist(candidate.CriticalArc));
}
}
// Execute this move & return.
origin.ExecuteMove(candidate);
return(origin);
}