public Solution NearestNeighbour(Customer[] customers, int deliverers)
{
Deliveryman[] d = new Deliveryman[deliverers];
for (int t = 0; t < d.Length; t++)
{
d[t] = new Deliveryman();
}
Point cur_pos = new Point(0, 0);
for (int x = 0; x < customers.Length / deliverers; x++)
{
int nearest_neighbour = -1;
int best_dist = int.MaxValue;
for (int t = 0; t < customers.Length; t++)
{
if (!visited[t])
{
int dist = Math.Abs(customers[t].X - cur_pos.X) + Math.Abs(customers[t].Y - cur_pos.Y);
if (dist < best_dist)
{
nearest_neighbour = customers[t].ID;
best_dist = dist;
}
}
}
d[0].route.Add(nearest_neighbour);
visited[nearest_neighbour - 1] = true;
cur_pos = new Point(customers[nearest_neighbour - 1].X, customers[nearest_neighbour - 1].Y);
}
return new Solution(customers, d);
}
public Solution EqualNeighbour(Customer[] customers, int deliverers)
{
Deliveryman[] ds = new Deliveryman[deliverers];
for (int t = 0; t < ds.Length; t++)
{
ds[t] = new Deliveryman();
}
for (int x = 0; x < customers.Length; x++)
{
int laziest = int.MaxValue;
Deliveryman l = null;
foreach (Deliveryman d in ds)
{
int score = 0;
Point cur_pos = new Point(0, 0);
foreach (int z in d.route)
{
int dist = Math.Abs(cs[z - 1].X - cur_pos.X) + Math.Abs(cs[z - 1].Y - cur_pos.Y);
score += dist;
cur_pos = new Point(cs[z - 1].X, cs[z - 1].Y);
}
score += Math.Abs(cur_pos.X - 0) + Math.Abs(cur_pos.Y - 0);
if (score < laziest)
{ laziest = score; l = d; }
}
for (int t = 0; t < ds.Length; t++)
{
if (ds[t] == l)
ds[t].route.Add(customers[x].ID);
}
}
return new Solution(customers, ds);
}
public Solution(Customer[] customers, Deliveryman[] d)
{
// customers, or 'map' of the problem
cs = customers;
// representation of the routes, by customer id's
rs = d;
// number of deliverymen
n = d.Length;
// rnd
rnd = new Random();
}
public Solution NextNeighbor(int g)
{
//Swap two nodes in the same route
if (g == 0)
{
Deliveryman[] rx = new Deliveryman[rs.Length];
for (int i = 0; i < rs.Length; i++)
{
rx[i] = new Deliveryman();
foreach (int c in rs[i].route)
rx[i].route.Add(c);
}
// Rnd route and nodes
int rnd_route = rnd.Next(0, n);
int rnd_nodeA = rnd.Next(0, rx[rnd_route].route.Count);
int rnd_nodeB = rnd.Next(0, rx[rnd_route].route.Count);
// Swap nodes
int a = rx[rnd_route].route[rnd_nodeA];
rx[rnd_route].route[rnd_nodeA] = rx[rnd_route].route[rnd_nodeB];
rx[rnd_route].route[rnd_nodeB] = a;
// Return new Solution
return new Solution(cs, rx);
}
//Move a node from one route to another
else if (g == 1)
{
Random r2 = new Random();
Deliveryman[] rx = new Deliveryman[rs.Length];
for (int i = 0; i < rs.Length; i++)
{
rx[i] = new Deliveryman();
foreach (int c in rs[i].route)
rx[i].route.Add(c);
}
int rnd_first = r2.Next(0, n); //Deliveryman to take customer from
int l_first = rx[rnd_first].route.Count();
int rnd_second = r2.Next(0, n); //Deliveryman to put customer in
int node_first = r2.Next(0, l_first); //Customer to move
//Add customer to new route and remove from initial one only if first route would not end up empty
if (rx[rnd_first].route.Count() - 1 > 1)
{
int r = rnd.Next(0, rx[rnd_second].route.Count);
rx[rnd_second].route.Insert(r, rx[rnd_first].route[node_first]);
//rx[rnd_second].route.Add(rx[rnd_first].route[node_first]);
rx[rnd_first].route.RemoveAt(node_first);
}
//Return new solution
return new Solution(cs, rx);
}
//Move node from one route to closest node from another route in the route
else if (g == 2)
{
Deliveryman[] rx = new Deliveryman[rs.Length];
for (int i = 0; i < rs.Length; i++)
{
rx[i] = new Deliveryman();
foreach (int c in rs[i].route)
rx[i].route.Add(c);
}
// randomly select two different routes
int route_a = rnd.Next(0, rx.Length);
int route_b = rnd.Next(0, rx.Length);
if (rx[route_a].route.Count > 0 && rx[route_b].route.Count > 0)
{
// select random node from route a
int index = rnd.Next(0, rx[route_a].route.Count - 1);
int node_a = rx[route_a].route.ElementAt(index);
// select node from route b that is closest to node a
int closest_node = 0;
int closest_value = int.MaxValue;
foreach (int node in rx[route_b].route)
{
int dist = (Math.Abs(cs[node_a - 1].X - cs[node - 1].X) + Math.Abs(cs[node_a - 1].Y - cs[node - 1].Y));
if (closest_value > dist && node != node_a)
{
closest_node = node;
closest_value = dist;
}
}
// add this node to route a
rx[route_a].route.Insert(index, closest_node);
rx[route_b].route.Remove(closest_node);
}
// return solution
return new Solution(cs, rx);
}
else
return new Solution(cs, rs);
}
public Solution RandomMultiple(Customer[] customers, int amount)
{
Deliveryman[] work = new Deliveryman[amount];
int path_length = 0;
if (customers.Length % amount == 0)
path_length = customers.Length / amount;
else
path_length = customers.Length / amount + 1;
for (int t = 0; t < work.Length; t++)
{
work[t] = new Deliveryman();
}
//Random r = new Random();
for (int t = 0; t < customers.Length; t++)
{
int x = r.Next(0, work.Length);
work[x].route.Add(customers[t].ID);
}
return new Solution(customers, work);
}
