private static void CreateCityListBasedOnNearestFirst(List <CityInfo> cityList, int startCityID, List <CityInfo> sample)
{
cityList.Add(sample.Find(city => city.ID == startCityID));
while (cityList.Count < sample.Count)
{
float distance = float.MaxValue;
CityInfo nextCity = cityList.First();
foreach (CityInfo city in sample)
{
if (cityList.Find(c => c.ID == city.ID) != null)
{
continue;
}
float temp = DistanceHelper.DistanceBetweenTwoPoints(city, cityList.Last());
if (temp < distance)
{
distance = temp;
nextCity = city;
}
}
cityList.Add(nextCity);
}
}
private static void CreateCityListBasedOnNearestInsertionHeuristic(List <CityInfo> cityList, int startCityID, List <CityInfo> sample)
{
//firstly, find the first two cities taht salesman will visit
//the fisrt city is based on the user choice, the second city is the city which is most closest to first city
CityInfo startCity = sample.Find(city => city.ID == startCityID);
cityList.Add(startCity);
CityInfo secondCity = sample[0];
float distance = float.MaxValue;
foreach (CityInfo city in sample)
{
if (city.ID == startCity.ID)
{
continue;
}
float temp = DistanceHelper.DistanceBetweenTwoPoints(startCity, city);
if (distance > temp)
{
secondCity = city;
distance = temp;
}
}
cityList.Add(secondCity);
//Closest Edge Insertion Heuristic
while (cityList.Count != sample.Count)
{
//Determine whether adding this city to the partial tour based on Closest Edge Insertion Heuristic
distance = float.MaxValue;
CityInfo nextCity = null;
int insertIndex = 0;
foreach (CityInfo potentialNextCity in sample)
{
if (cityList.Exists(c => c.ID == potentialNextCity.ID))
{
//if the city is already visited, skip it
continue;
}
//compute the distance between potentialNextCity with all edge in the partial tour
for (int i = 0; i < cityList.Count - 1; i++)
{
float temp = DistanceHelper.DistanceFromPointToLine(cityList[i], cityList[i + 1], potentialNextCity);
if (temp < distance)
{
distance = temp;
nextCity = potentialNextCity;
insertIndex = i + 1;
}
}
}
cityList.Insert(insertIndex, nextCity);
}
}
static bool AreaCheck(CityInfo cityOne, CityInfo cityTwo, CityInfo cityThree, CityInfo cityFour)
{
float areaOne, areaTwo;
areaOne = 0.5f * DistanceHelper.DistanceBetweenTwoPoints(cityOne, cityThree) * (DistanceHelper.DistanceFromPointToLine(cityOne, cityThree, cityTwo) + DistanceHelper.DistanceFromPointToLine(cityOne, cityThree, cityFour));
areaTwo = 0.5f * DistanceHelper.DistanceBetweenTwoPoints(cityTwo, cityFour) * (DistanceHelper.DistanceFromPointToLine(cityTwo, cityFour, cityOne) + DistanceHelper.DistanceFromPointToLine(cityTwo, cityFour, cityThree));
return(areaOne == areaTwo ? true : false);
}
private void RefreshList()
{
currentPopulation[0] = initialCityListOne;
currentPopulation[1] = initialCityListTwo;
currentPopulation[2] = initialCityListThree;
currentPopulation[3] = initialCityListFour;
currentDistances[0] = DistanceHelper.TotalDistance(initialCityListOne);
currentDistances[1] = DistanceHelper.TotalDistance(initialCityListTwo);
currentDistances[2] = DistanceHelper.TotalDistance(initialCityListThree);
currentDistances[3] = DistanceHelper.TotalDistance(initialCityListFour);
RefreshPicBox(initialCityListOne);
}
public static void Evolution(ref List <CityInfo>[] previousPopulation, ref float[] previousDistances, int crossoverSelection, float mutationPossibility)
{
float[] fitnesses = Fitness(previousDistances);
List <CityInfo>[] selected = Selection(previousPopulation, fitnesses);
List <CityInfo>[] nextPopulation = Crossover(selected, crossoverSelection);
Mutation(ref nextPopulation, mutationPossibility);
float[] nextDistances = new float[4];
for (int i = 0; i < nextPopulation.Count(); i++)
{
nextDistances[i] = DistanceHelper.TotalDistance(nextPopulation[i]);
}
Elimination(ref previousDistances, ref nextDistances, ref previousPopulation, ref nextPopulation);
previousPopulation = nextPopulation;
previousDistances = nextDistances;
}