//if cities is null, O(n), otherwise O(n^3)
public Population(int populationSize, City[] cities = null)
{
if (cities != null)
{
Greedy g = new Greedy();
//O(n^3)
List <ArrayList> greedyRoutes = g.getRoutes(cities);
//shuffle routes
//O(n)
int n = greedyRoutes.Count;
while (n > 1)
{
n--;
int k = rng.Next(n + 1);
ArrayList value = greedyRoutes[k];
greedyRoutes[k] = greedyRoutes[n];
greedyRoutes[n] = value;
}
//worst O(m*n) where m is population size and n is number of cities
if (populationSize > greedyRoutes.Count)
{
routes = new List <ArrayList>();
for (int i = 0; i < greedyRoutes.Count; i++)
{
routes.Add(new ArrayList());
routes[i] = greedyRoutes[i];
}
for (int i = greedyRoutes.Count; i < populationSize; i++)
{
routes.Add(new ArrayList());
//O(n)
routes[i] = Spawn(cities);
}
}
//O(k)
else
{
routes = greedyRoutes.GetRange(0, populationSize);
}
}
//O(n) where n is population size
else
{
routes = new List <ArrayList>();
for (int i = 0; i < populationSize; i++)
{
routes.Add(new ArrayList());
//this is to see if the constructor should spawn or not - this was for previous version that did not use the greedy results as population. Now unreachable
if (cities != null)
{
routes[i] = Spawn(cities);
}
}
}
}
/////////////////////////////////////////////////////////////////////////////////////////////
// These additional solver methods will be implemented as part of the group project.
////////////////////////////////////////////////////////////////////////////////////////////
/// <summary>
/// finds the greedy tour starting from each city and keeps the best (valid) one
/// </summary>
/// <returns>results array for GUI that contains three ints: cost of solution, time spent to find solution, number of solutions found during search (not counting initial BSSF estimate)</returns>
public string[] greedySolveProblem()
{
string[] results = new string[3];
Greedy g = new Greedy();
ArrayList route;
string time;
g.solve(out route, Cities, out time);
bssf = new TSPSolution(route);
results[COST] = bssf.costOfRoute().ToString(); // load results into array here, replacing these dummy values
results[TIME] = time;
results[COUNT] = "0";
return(results);
}
