private Population InitPopulation()
{
Population pop = new Population();
pop.Add(new Sequence(parent.BSSF));
City[] cities = parent.GetCities();
City start = cities[0];
GreedyMaker maker = new GreedyMaker(cities);
List <City> greedy = new List <City>();
City source = start;
greedy.Add(source);
while (greedy.Count < cities.Length)
{
var destinations = maker[source];
foreach (var c in destinations)
{
City gcity = c.Destination;
if (!greedy.Contains(gcity))
{
greedy.Add(gcity);
source = gcity;
break;
}
}
}
pop.Add(new Sequence(greedy));
while (pop.Size < PopulationSize)
{
City city = start;
List <City> gene = new List <City>();
while (gene.Count < cities.Length)
{
if (!gene.Contains(city))
{
gene.Add(city);
}
city = maker[city][(random.Next() <= GreedyPreferenceRate ?
random.Next(GreedyVariance) :
random.Next(maker[city].Count))].Destination;
}
pop.Add(new Sequence(gene));
}
return(pop);
}
public string[] Solve(ProblemAndSolver parent)
{
this.parent = parent;
string[] results = new string[3];
Dictionary <string, double> improvementRate = new Dictionary <string, double>();
Population pop = InitPopulation();
Sequence imdabest = pop.Best;
Stopwatch timer = new Stopwatch();
improvementRate[timer.Elapsed.ToString()] = imdabest.Score;
timer.Start();
int iterationsSanChangement = 0;
int count = 0;
int generations = 0;
List <Sequence> bestones = new List <Sequence>();
bestones.Add(imdabest);
while ((iterationsSanChangement < MaxGenerations && timer.Elapsed.TotalSeconds < 90) ||
pop.Size < 2)
{
generations++;
CrossPopulation(ref pop);
MutatePopulation(pop);
PrunePopulation(pop);
if (pop.Best.Score < imdabest.Score)
{
iterationsSanChangement = 0;
count++;
imdabest = pop.Best;
improvementRate[timer.Elapsed.ToString()] = imdabest.Score;
bestones.Add(imdabest);
}
else
{
iterationsSanChangement++;
}
}
timer.Stop();
parent.BSSF = imdabest.ToRoute();
Console.WriteLine();
results[ProblemAndSolver.COST] = imdabest.Score.ToString(); // load results into array here, replacing these dummy values
results[ProblemAndSolver.TIME] = timer.Elapsed.ToString();
results[ProblemAndSolver.COUNT] = count.ToString(); //*** should this be 1 or the number of greedy solutions that we find???
StringBuilder bob = new StringBuilder();
bob.Append("Time,Best Cost\r\n");
foreach (var entry in improvementRate)
{
bob.Append(entry.Key);
bob.Append(",");
bob.Append(entry.Value);
bob.Append("\r\n");
}
bob.Append("Best," + imdabest.Score.ToString() + "\r\n");
bob.Append("Problem Size," + parent.GetCities().Length + "\r\n");
bob.Append("Seed," + parent.Seed + "\r\n");
bob.Append("Generations," + generations.ToString() + "\r\n");
bob.Append("Total Time," + timer.Elapsed.ToString());
bob.Append("\r\n");
System.IO.File.AppendAllText(@"C:\Users\Matt\Desktop\tsp_results.csv", bob.ToString());
return(results);
}
