protected override IEnumerable <Tuple <IIndividual, IIndividual> > SelectForCrossing(
List <IIndividual> currentPopulation)
{
var numPairs = currentPopulation.Count / 2;
var resultingPairs = new List <Tuple <IIndividual, IIndividual> >();
for (var i = 0; i < numPairs; i++)
{
var firstIndiv = TournamentSelect(currentPopulation) as Ttp1Individual;
var secondIndiv = TournamentSelect(currentPopulation) as Ttp1Individual;
if (firstIndiv == null || secondIndiv == null)
{
Console.WriteLine("Wrong type of individuals population passed to TTP1. It need TTP2 population.");
return(null);
}
while (secondIndiv.RoadTaken.Equals(firstIndiv.RoadTaken))
{
secondIndiv =
currentPopulation[RandomNumGenerator.Next(0, currentPopulation.Count)] as Ttp1Individual;
if (secondIndiv != null)
{
continue;
}
Console.WriteLine("Wrong type of individuals population passed to TTP1. It need TTP2 population.");
return(null);
}
resultingPairs.Add(new Tuple <IIndividual, IIndividual>(firstIndiv, secondIndiv));
}
return(resultingPairs);
}
public override List <IIndividual> InitializePopulation()
{
var population = new List <IIndividual>();
var numCities = Problem.CityIds.Count;
for (var i = 0; i < Parameters.PopulationSize; i++)
{
var randomRoadTaken = new List <int>(numCities);
var mutableListCityIds = new List <int>(Problem.CityIds);
for (var j = 0; j < numCities; j++)
{
var randomIndex = RandomNumGenerator.Next(0, mutableListCityIds.Count);
var randomCityId = mutableListCityIds[randomIndex];
mutableListCityIds.RemoveAt(randomIndex);
randomRoadTaken.Add(randomCityId);
}
var individual = new Ttp1Individual(randomRoadTaken);
population.Add(individual);
}
return(population);
}
protected override IIndividual MutateIndividual(IIndividual indiv, bool guaranteedMutation = false)
{
if (!guaranteedMutation && !ShouldMutate())
{
return(indiv);
}
if (!(indiv is Ttp1Individual indivTtp1))
{
Console.WriteLine("Wrong type of individuals population passed to TTP1. It need TTP2 population.");
return(null);
}
var firstRandomSwapIndex = RandomNumGenerator.Next(0, indivTtp1.RoadTaken.Count);
var secondRandomSwapIndex = RandomNumGenerator.Next(0, indivTtp1.RoadTaken.Count);
while (firstRandomSwapIndex == secondRandomSwapIndex)
{
secondRandomSwapIndex = RandomNumGenerator.Next(0, indivTtp1.RoadTaken.Count);
}
var tmp = indivTtp1.RoadTaken[firstRandomSwapIndex];
indivTtp1.RoadTaken[firstRandomSwapIndex] = indivTtp1.RoadTaken[secondRandomSwapIndex];
indivTtp1.RoadTaken[secondRandomSwapIndex] = tmp;
return(indiv);
}
private IIndividual CrossPmx(IIndividual parent1, IIndividual parent2)
{
var child = parent1.DeepCopy();
if (!(parent1 is Ttp1Individual parent1Ttp1) || !(parent2 is Ttp1Individual parent2Ttp1) ||
!(child is Ttp1Individual childTtp1))
{
return(child);
}
if (parent1Ttp1.RoadTaken.Count != parent2Ttp1.RoadTaken.Count)
{
return(childTtp1);
}
var roadLength = parent1Ttp1.RoadTaken.Count;
var road1 = parent1Ttp1.RoadTaken;
var road2 = parent1Ttp1.RoadTaken;
var firstChildFirstCutIndex = RandomNumGenerator.Next(0, roadLength);
var firstChildSecondCutIndex = RandomNumGenerator.Next(firstChildFirstCutIndex, roadLength);
var cutValuesFromIndiv1 =
road1.GetRange(firstChildFirstCutIndex, firstChildSecondCutIndex - firstChildFirstCutIndex);
var cutValuesFromIndiv2 = road2
.GetRange(firstChildFirstCutIndex, firstChildSecondCutIndex - firstChildFirstCutIndex)
.Where(valueFromIndiv2 => !cutValuesFromIndiv1.Contains(valueFromIndiv2)).ToList();
foreach (var value in cutValuesFromIndiv2)
{
var currentValueFromIndiv2 = value;
var valueAtTheSamePositionInIndiv1 =
road1[road2.IndexOf(currentValueFromIndiv2)];
var indexOfThatValueInIndiv2 = road2.IndexOf(valueAtTheSamePositionInIndiv1);
while (indexOfThatValueInIndiv2 >= firstChildFirstCutIndex ||
indexOfThatValueInIndiv2 < firstChildSecondCutIndex)
{
currentValueFromIndiv2 = road1[indexOfThatValueInIndiv2];
valueAtTheSamePositionInIndiv1 =
road1[road2.IndexOf(currentValueFromIndiv2)];
indexOfThatValueInIndiv2 = road2.IndexOf(valueAtTheSamePositionInIndiv1);
}
childTtp1.RoadTaken[indexOfThatValueInIndiv2] = value;
}
var valuesLeftInIndiv2 = road2.Where(value => !cutValuesFromIndiv1.Contains(value) &&
!cutValuesFromIndiv2.Contains(value)).ToList();
var indexInIndiv1 = 0;
foreach (var valueLeftInIndiv2 in valuesLeftInIndiv2)
{
var insertedValue = false;
while (indexInIndiv1 < roadLength && !insertedValue)
{
var valueFromIndiv1 = childTtp1.RoadTaken[indexInIndiv1];
if (cutValuesFromIndiv1.Contains(valueFromIndiv1) || cutValuesFromIndiv2.Contains(valueFromIndiv1))
{
indexInIndiv1++;
continue;
}
childTtp1.RoadTaken[indexInIndiv1] = valueLeftInIndiv2;
indexInIndiv1++;
insertedValue = true;
}
}
return(childTtp1);
}