/// <summary>
/// Calculates the weight for a part of the tour including the turns at first and last position.
/// </summary>
/// <param name="part">The part to calculate for.</param>
/// <param name="timeBefore">The time when arriving at the first customer, excluding the turn at that first customer.</param>
public int TimeAndViolationsForPart(IEnumerable <int> part, float timeBefore, out float time, out float waitTime, out float violatedTime, ref bool[] validFlags)
{
var times = this.Times;
var windows = this.Windows;
var turnPenalties = this.TurnPenalties;
time = timeBefore;
violatedTime = 0f;
waitTime = 0f;
var violated = 0;
var previousFrom = int.MaxValue;
foreach (var directedId in part)
{
// extract turns and stuff from directed id.
int arrivalId, departureId, id, turn;
DirectedHelper.ExtractAll(directedId, out arrivalId, out departureId, out id, out turn);
// add the weight from the previous customer to the current one.
var turnPenalty = 0f;
if (previousFrom != int.MaxValue)
{ // there is a previous, add the travel time.
time = time + times[previousFrom][arrivalId];
// and keep the turn penalty.
turnPenalty += turnPenalties[turn];
}
else
{ // first customer.
// add turn penalty at first customer.
time += turnPenalties[DirectedHelper.ExtractTurn(directedId)];
}
// check the windows (before turn-penalties).
var window = windows[id];
validFlags[id] = true;
if (window.Max < (time + waitTime))
{ // ok, unfeasible.
violatedTime += (time + waitTime) - window.Max;
validFlags[id] = false;
violated++;
}
if (window.Min > (time + waitTime))
{ // wait here!
waitTime += (window.Min - (time + waitTime));
}
// add the turn penalty.
time += turnPenalty;
previousFrom = departureId;
}
time = time - timeBefore; // correct the time again, the time returned is the time of only this part.
return(violated);
}
/// <summary>
/// Calculates the fitness value of the given solution.
/// </summary>
public sealed override float Calculate(TSProblem problem, Tour solution)
{
if (solution.Count == 1)
{
return(0);
}
var isLoop = solution.Last == solution.First;
var weights = problem.Weights;
var weight = 0f;
var previousFrom = int.MaxValue;
var firstTo = int.MaxValue;
var lastTurn = 0f;
foreach (var directedId in solution)
{
// extract turns and stuff from directed id.
int arrivalId, departureId, id, turn;
DirectedHelper.ExtractAll(directedId, out arrivalId, out departureId, out id, out turn);
// add the weight from the previous customer to the current one.
if (previousFrom != int.MaxValue)
{
weight = weight + weights[previousFrom][arrivalId];
}
else
{
firstTo = arrivalId;
}
// add turn penalty.
if (isLoop || id != problem.First)
{
lastTurn = problem.TurnPenalties[turn];
weight += lastTurn;
}
previousFrom = departureId;
}
if (solution.Last == null)
{
weight -= lastTurn;
}
// add the weight between last and first.
if (previousFrom != int.MaxValue &&
isLoop)
{
weight = weight + weights[previousFrom][firstTo];
}
return(weight);
}
/// <summary>
/// Calculates the fitness value of the given solution.
/// </summary>
public sealed override STSPFitness Calculate(STSProblem problem, Tour solution)
{
// TODO: unittest this stuff!
var fitness = new STSPFitness()
{
Customers = solution.Count,
Weight = 0
};
var weights = problem.Weights;
var weight = 0f;
var previousFrom = int.MaxValue;
var firstTo = int.MaxValue;
foreach (var directedId in solution)
{
// extract turns and stuff from directed id.
int arrivalId, departureId, id, turn;
DirectedHelper.ExtractAll(directedId, out arrivalId, out departureId, out id, out turn);
// add the weight from the previous customer to the current one.
if (previousFrom != int.MaxValue)
{
weight = weight + weights[previousFrom][arrivalId];
}
else
{
firstTo = arrivalId;
}
// add turn penalty.
weight += problem.TurnPenalties[turn];
previousFrom = departureId;
}
// add the weight between last and first.
if (previousFrom != int.MaxValue &&
solution.First == solution.Last)
{
weight = weight + weights[previousFrom][firstTo];
}
fitness.Weight = weight;
return(fitness);
}
/// <summary>
/// Calculates the fitness value of the given solution.
/// </summary>
public sealed override float Calculate(SequenceDirectedProblem problem, Tour solution)
{
var weights = problem.Weights;
var weight = 0f;
var previousFrom = int.MaxValue;
var firstTo = int.MaxValue;
foreach (var directedId in solution)
{
// extract turns and stuff from directed id.
int arrivalId, departureId, id, turn;
DirectedHelper.ExtractAll(directedId, out arrivalId, out departureId, out id, out turn);
// add the weight from the previous customer to the current one.
if (previousFrom != int.MaxValue)
{
weight = weight + weights[previousFrom][arrivalId];
}
else
{
firstTo = arrivalId;
}
// add turn penalty.
weight += problem.TurnPenalties[turn];
previousFrom = departureId;
}
// add the weight between last and first.
if (previousFrom != int.MaxValue &&
solution.First == solution.Last)
{
weight = weight + weights[previousFrom][firstTo];
}
return(weight);
}
/// <summary>
/// Applies this operator.
/// </summary>
public bool Apply(SequenceDirectedProblem problem, SequenceDirectedObjective objective, Tour solution, out float delta)
{
var weights = problem.Weights;
delta = objective.Zero;
var fitnessBefore = objective.Calculate(problem, solution);
var enumerator = solution.GetEnumerator();
while (enumerator.MoveNext())
{
var previous = enumerator.Current;
var previousDepartureId = DirectedHelper.ExtractDepartureId(previous);
var current = solution.GetNeigbour(previous);
if (current == Constants.NOT_SET)
{ // last of open.
continue;
}
var next = solution.GetNeigbour(current);
var nextArrivalId = Constants.NOT_SET;
if (next != Constants.NOT_SET)
{
nextArrivalId = DirectedHelper.ExtractArrivalId(next);
}
int currentTurn, currentId, currentArrivalId, currentDepartureId;
DirectedHelper.ExtractAll(current, out currentArrivalId, out currentDepartureId, out currentId, out currentTurn);
var weightBefore = weights[previousDepartureId][currentArrivalId];
var weightAfter = float.MaxValue;
var newDirectedId = Constants.NOT_SET;
if (next == Constants.NOT_SET)
{ // there is no next, only one option here:
// 0 or 1: arrival id offset = 0 OR
// 2 or 3: arrival id offset = 1
if (currentArrivalId % 2 == 0)
{ // check turn = 2.
weightAfter = weights[previousDepartureId][currentArrivalId + 1];
if (weightAfter < weightBefore)
{ // do the switch.
newDirectedId = DirectedHelper.BuildDirectedId(currentId, 2);
}
}
else
{ // check turn = 0
weightAfter = weights[previousDepartureId][currentArrivalId - 1];
if (weightAfter < weightBefore)
{ // do the switch.
newDirectedId = DirectedHelper.BuildDirectedId(currentId, 0);
}
}
}
else
{ // three options left, excluding the current one of 4.
weightBefore += weights[currentDepartureId][nextArrivalId];
weightBefore += problem.TurnPenalties[currentTurn];
currentArrivalId = currentArrivalId - (currentArrivalId % 2);
currentDepartureId = currentDepartureId - (currentDepartureId % 2);
for (var i = 0; i < 4; i++)
{
if (i == currentTurn)
{
continue;
}
int arrivalOffset, departureOffset;
DirectedHelper.ExtractOffset(i, out arrivalOffset, out departureOffset);
var newWeightAfter = weights[previousDepartureId][currentArrivalId + arrivalOffset]
+ weights[currentDepartureId + departureOffset][nextArrivalId]
+ problem.TurnPenalties[i];
if (newWeightAfter < weightAfter &&
newWeightAfter < weightBefore)
{
newDirectedId = DirectedHelper.BuildDirectedId(currentId, i);
weightAfter = newWeightAfter;
}
}
}
// switch if a new directed if was found.
if (newDirectedId != Constants.NOT_SET)
{
solution.Replace(current, newDirectedId);
}
}
var fitnessAfter = objective.Calculate(problem, solution);
delta = objective.Subtract(problem, fitnessBefore, fitnessAfter);
return(objective.CompareTo(problem, delta, objective.Zero) > 0);
}
/// <summary>
/// Returns true if there was an improvement, false otherwise.
/// </summary>
/// <returns></returns>
public bool Apply(TSPTWProblem problem, TSPTWObjective objective, Tour tour, out float delta)
{
delta = 0;
var fitness = objective.Calculate(problem, tour);
var customers = new List <int>(problem.Times.Length + 1);
customers.AddRange(tour);
if (tour.Last == tour.First)
{ // add last customer at the end if it's the same as the first one.
customers.Add(tour.Last.Value);
}
// select two edges with at least one edge between them at both sides of the tour.
var weightBefore = 0f;
if (problem.Windows[DirectedHelper.ExtractId(customers[0])].Min > weightBefore)
{ // wait here!
weightBefore = problem.Windows[DirectedHelper.ExtractId(customers[0])].Min;
}
for (var edge1 = 0; edge1 < customers.Count - 3; edge1++)
{ // iterate over all from-edges.
var edge11 = customers[edge1 + 0];
var edge12 = customers[edge1 + 1];
// extract directional information.
int edge11arrivalId, edge11departureId, edge11id, edge11turn;
DirectedHelper.ExtractAll(edge11, out edge11arrivalId, out edge11departureId, out edge11id, out edge11turn);
int edge12arrivalId, edge12departureId, edge12id, edge12turn;
DirectedHelper.ExtractAll(edge12, out edge12arrivalId, out edge12departureId, out edge12id, out edge12turn);
for (var edge2 = edge1 + 2; edge2 < customers.Count - 1; edge2++)
{ // iterate over all possible to-edges given the from-edge.
var edge21 = customers[edge2 + 0];
var edge22 = customers[edge2 + 1];
// at this point we have two edges 11->12->...->21->22->...
// attempt to reverse the part in between.
// 1: calculate the reverse part and check if feasible.
// 2: if not feasible then stop.
// 3: if feasible then calculate the forward part.
// 4: if better then accept the result.
// calculate het best possible reverse sequence by switching turns and departure and arrivel id's.
// First start by creating a sequence with all turns and arrival and departure id's equal to zero.
var part = new List <int>();
part.Add(DirectedHelper.UpdateDepartureOffset(edge11, 0));
for (var b = edge2; b > edge1; b--)
{
part.Add(DirectedHelper.BuildDirectedId(DirectedHelper.ExtractId(customers[b]), 0));
}
part.Add(DirectedHelper.UpdateArrivalOffset(edge22, 0));
var localDelta = this.OptimizePart(problem, part);
while (localDelta > 0.1)
{
localDelta = this.OptimizePart(problem, part);
}
int violated;
float violatedTime, waitTime;
var partTime = objective.CalculateTimeForPart(problem, part, weightBefore, out violated, out violatedTime, out waitTime);
if (violated == 0)
{ // new part is feasible, this should be fine.
var existingPart = new List <int>();
existingPart.Add(edge11);
for (var c = edge1 + 1; c < edge2; c++)
{
existingPart.Add(customers[c]);
}
existingPart.Add(edge22);
var existingPartTime = objective.CalculateTimeForPart(problem, existingPart, weightBefore, out violated, out violatedTime, out waitTime);
if (existingPartTime > partTime)
{ // an improvment, add the new part.
tour.Replace(edge11, part[0]);
tour.Replace(edge22, part[part.Count - 1]);
for (var c = 1; c < part.Count; c++)
{
tour.ReplaceEdgeFrom(part[c - 1], part[c]);
}
var newFitness = objective.Calculate(problem, tour);
delta = fitness - newFitness;
return(true);
}
}
}
// update weight before.
weightBefore += problem.Times[edge11arrivalId][edge12arrivalId];
weightBefore += problem.TurnPenalties[edge11turn];
if (problem.Windows[DirectedHelper.ExtractId(customers[edge1])].Min > weightBefore)
{ // wait here!
weightBefore = problem.Windows[DirectedHelper.ExtractId(customers[edge1])].Min;
}
}
return(false);
}
/// <summary>
/// Optimizes the given part of the tour by choosing the best improvements in either the departureOffset or arrivalOffset of the first/last customers or the turns at any of the intermediate ones.
/// </summary>
private float OptimizePart(TSPTWProblem problem, List <int> part)
{
int turn1, arrivalId1, departureId1, id1;
int turn2, arrivalId2, departureId2, id2;
int turn3, arrivalId3, departureId3, id3;
var delta = 0f; // the positive difference.
var arrivalIdChange = -1;
var departureIdChange = -1;
var customerIdx = -1;
var customerTurn = -1;
// try changing the departureId.
DirectedHelper.ExtractAll(part[0], out arrivalId1, out departureId1, out id1, out turn1);
DirectedHelper.ExtractAll(part[1], out arrivalId2, out departureId2, out id2, out turn2);
var weight = problem.TurnPenalties[turn1];
weight += problem.Times[departureId1][arrivalId2];
var new0 = DirectedHelper.SwitchDepartureOffset(part[0]);
DirectedHelper.ExtractAll(new0, out arrivalId3, out departureId3, out id3, out turn3);
var newWeight = problem.TurnPenalties[turn3];
newWeight += problem.Times[departureId3][arrivalId2];
if (newWeight < weight)
{ // there was an improvement found in changing the departure id.
departureIdChange = DirectedHelper.ExtractDepartureId(new0);
delta = newWeight - weight;
}
// try changing the arrivalId.
DirectedHelper.ExtractAll(part[part.Count - 2], out arrivalId1, out departureId1, out id1, out turn1);
DirectedHelper.ExtractAll(part[part.Count - 1], out arrivalId2, out departureId2, out id2, out turn2);
weight = problem.TurnPenalties[turn2];
weight += problem.Times[departureId1][arrivalId2];
var newLast = DirectedHelper.SwitchArrivalOffset(part[part.Count - 1]);
DirectedHelper.ExtractAll(newLast, out arrivalId3, out departureId3, out id3, out turn3);
newWeight = problem.TurnPenalties[turn3];
newWeight += problem.Times[departureId1][arrivalId3];
if (newWeight < weight &&
delta < (newWeight - weight))
{ // there was an improvement found in changing the arrival id.
arrivalIdChange = DirectedHelper.ExtractDepartureId(newLast);
departureIdChange = -1;
delta = newWeight - weight;
}
for (var c = 1; c < part.Count - 1; c++)
{
var perviousDepartureId = DirectedHelper.ExtractDepartureId(part[c - 1]);
DirectedHelper.ExtractAll(part[c], out arrivalId1, out departureId1, out id1, out turn1);
var nextArrivalid = DirectedHelper.ExtractArrivalId(part[c + 1]);
weight = problem.Times[perviousDepartureId][arrivalId1];
weight += problem.TurnPenalties[turn1];
weight += problem.Times[departureId1][nextArrivalid];
for (var t = 0; t < 3; t++)
{
if (t == turn1)
{
continue;
}
var newDirectedId = DirectedHelper.BuildDirectedId(id1, t);
DirectedHelper.ExtractAll(newDirectedId, out arrivalId2, out departureId2, out id2, out turn2);
newWeight = problem.Times[perviousDepartureId][arrivalId2];
newWeight += problem.TurnPenalties[turn2];
newWeight += problem.Times[departureId2][nextArrivalid];
if (newWeight < weight &&
delta < (newWeight - weight))
{ // there was an improvement found in changing the turn.
arrivalIdChange = -1;
departureIdChange = -1;
customerIdx = c;
customerTurn = t;
delta = newWeight - weight;
}
}
}
if (delta > 0)
{
if (departureIdChange != -1)
{
part[0] = DirectedHelper.SwitchDepartureOffset(part[0]);
}
else if (arrivalIdChange != -1)
{
part[part.Count - 1] = DirectedHelper.SwitchArrivalOffset(part[part.Count - 1]);
}
else if (customerIdx != -1)
{
part[customerIdx] = DirectedHelper.BuildDirectedId(
DirectedHelper.ExtractId(part[customerIdx]), customerTurn);
}
}
return(delta);
}
/// <summary>
/// Gets the minimum weight from customer1 -> customer3 while inserting customer2 and the best direction and turns to use.
/// </summary>
public static float CalculateCheapestInsert(this float[][] weights, float[] penalties, int directedId1, int id2, int directedId3,
bool includeTurn1, bool includeTurn3, out int departureOffset1, out int arrivalOffset3, out int turn2)
{
// extract existing data.
int id1, turn1, arrivalId1, departureId1, arrivalOffset1, temp;
DirectedHelper.ExtractAll(directedId1, out arrivalId1, out departureId1, out id1, out turn1);
DirectedHelper.ExtractOffset(turn1, out arrivalOffset1, out temp);
int id3, turn3, arrivalId3, departureId3, departureOffset3;
DirectedHelper.ExtractAll(directedId3, out arrivalId3, out departureId3, out id3, out turn3);
DirectedHelper.ExtractOffset(turn3, out temp, out departureOffset3);
// calculate current weight.
var weightBefore = weights[departureId1][arrivalId3];
if (includeTurn1)
{
weightBefore += penalties[turn1];
}
if (includeTurn3)
{
weightBefore += penalties[turn3];
}
// evaluate all possibilities.
var best = float.MaxValue;
var base1 = id1 * 2;
var base2 = id2 * 2;
var base3 = id3 * 2;
departureOffset1 = Constants.NOT_SET;
arrivalOffset3 = Constants.NOT_SET;
turn2 = Constants.NOT_SET;
for (var do1 = 0; do1 < 2; do1++)
{
var d1 = base1 + do1;
var turn1Weight = 0f;
if (includeTurn1)
{
turn1 = DirectedHelper.BuildTurn(arrivalOffset1, do1);
turn1Weight = penalties[turn1];
}
for (var ao3 = 0; ao3 < 2; ao3++)
{
var a3 = base3 + ao3;
var turn3Weight = 0f;
if (includeTurn3)
{
turn3 = DirectedHelper.BuildTurn(departureOffset3, ao3);
turn3Weight = penalties[turn3];
}
for (var t = 0; t < 4; t++)
{
int ao2, do2;
DirectedHelper.ExtractOffset(t, out ao2, out do2);
var weight = weights[d1][base2 + ao2] +
weights[base2 + do2][a3] +
penalties[t] + turn1Weight +
turn3Weight;
if (weight < best)
{
best = weight;
departureOffset1 = do1;
arrivalOffset3 = ao3;
turn2 = t;
}
}
}
}
return best - weightBefore;
}
/// <summary>
/// Calculates total time and violations if the given id was moved after 'before'. Assumes the tour is closed.
/// </summary>
public int TimeAndViolations(IEnumerable <int> tour, out float time, out float waitTime, out float violatedTime, ref bool[] validFlags)
{
var times = this.Times;
var windows = this.Windows;
var turnPenalties = this.TurnPenalties;
time = 0f;
violatedTime = 0f;
waitTime = 0f;
var violated = 0;
var previousFrom = int.MaxValue;
var firstTo = int.MaxValue;
var first = Constants.NOT_SET;
foreach (var directedId in tour)
{
if (first == Constants.NOT_SET)
{
first = directedId;
}
// extract turns and stuff from directed id.
int arrivalId, departureId, id, turn;
DirectedHelper.ExtractAll(directedId, out arrivalId, out departureId, out id, out turn);
// add the weight from the previous customer to the current one.
var turnPenalty = 0f;
if (previousFrom != int.MaxValue)
{ // there is a previous, add the travel time.
time = time + times[previousFrom][arrivalId];
// and keep the turn penalty.
turnPenalty += turnPenalties[turn];
}
else
{ // first customer.
firstTo = arrivalId;
}
// check the windows (before turn-penalties).
var window = windows[id];
validFlags[id] = true;
if (window.Max < (time + waitTime))
{ // ok, unfeasible.
violatedTime += (time + waitTime) - window.Max;
validFlags[id] = false;
violated++;
}
if (window.Min > (time + waitTime))
{ // wait here!
waitTime += (window.Min - (time + waitTime));
}
// add the turn penalty.
time += turnPenalty;
previousFrom = departureId;
}
// add the weight between last and first.
if (previousFrom != int.MaxValue)
{
time = time + times[previousFrom][firstTo];
// add turn penalty at first customer.
time += turnPenalties[DirectedHelper.ExtractTurn(first)];
}
return(violated);
}
/// <summary>
/// Applies this operator.
/// </summary>
public bool Apply(TSProblem problem, TSPObjective objective, Tour solution, out float delta)
{
if (problem.Weights.Length <= 2)
{
delta = 0;
return(false);
}
var weights = problem.Weights;
delta = 0;
// test switching directions in random order.
if (_pool == null || solution.Count != _pool.Size)
{ // create a new pool.
_pool = new RandomPool(solution.Count);
}
else
{ // just reset the existing one.
_pool.Reset();
}
while (_pool.MoveNext())
{
var previous = solution.GetDirectedId(_pool.Current);
var previousDepartureId = DirectedHelper.ExtractDepartureId(previous);
var current = solution.GetNeigbour(previous);
if (current == Constants.NOT_SET)
{ // last of open.
continue;
}
var next = solution.GetNeigbour(current);
var nextArrivalId = Constants.NOT_SET;
if (next != Constants.NOT_SET)
{
nextArrivalId = DirectedHelper.ExtractArrivalId(next);
}
int currentTurn, currentId, currentArrivalId, currentDepartureId;
DirectedHelper.ExtractAll(current, out currentArrivalId, out currentDepartureId, out currentId, out currentTurn);
var weightBefore = weights[previousDepartureId][currentArrivalId];
var weightAfter = float.MaxValue;
var newDirectedId = Constants.NOT_SET;
if (next == Constants.NOT_SET)
{ // there is no next, only one option here:
// 0 or 1: arrival id offset = 0 OR
// 2 or 3: arrival id offset = 1
if (currentArrivalId % 2 == 0)
{ // check turn = 2.
weightAfter = weights[previousDepartureId][currentArrivalId + 1];
if (weightAfter < weightBefore)
{ // do the switch.
newDirectedId = DirectedHelper.BuildDirectedId(currentId, 2);
}
}
else
{ // check turn = 0
weightAfter = weights[previousDepartureId][currentArrivalId - 1];
if (weightAfter < weightBefore)
{ // do the switch.
newDirectedId = DirectedHelper.BuildDirectedId(currentId, 0);
}
}
}
else
{ // three options left, excluding the current one of 4.
weightBefore += weights[currentDepartureId][nextArrivalId];
weightBefore += problem.TurnPenalties[currentTurn];
currentArrivalId = currentArrivalId - (currentArrivalId % 2);
currentDepartureId = currentDepartureId - (currentDepartureId % 2);
for (var i = 0; i < 4; i++)
{
if (i == currentTurn)
{
continue;
}
int arrivalOffset, departureOffset;
DirectedHelper.ExtractOffset(i, out arrivalOffset, out departureOffset);
var newWeightAfter = weights[previousDepartureId][currentArrivalId + arrivalOffset]
+ weights[currentDepartureId + departureOffset][nextArrivalId]
+ problem.TurnPenalties[i];
if (newWeightAfter < weightAfter &&
newWeightAfter < weightBefore)
{
newDirectedId = DirectedHelper.BuildDirectedId(currentId, i);
weightAfter = newWeightAfter;
}
}
}
// switch if a new directed if was found.
if (newDirectedId != Constants.NOT_SET)
{
delta = weightAfter - weightBefore; // negative when improvement.
solution.Replace(current, newDirectedId);
}
}
return(delta < 0);
}