protected override int ChooseNext(Route route)
{
if (route.Count == 0)
{
return(0);
}
if (_testRoute == null || _testRoute.Graph != route.Graph)
{
_testRoute = new Route(route.Graph);
}
int best = -1;
int bestVal = -1;
int score = Int32.MaxValue;
for (int i = route.Count; i < route.Graph.Count; ++i)
{
int val = route.GetFromSelectionBuffer(i);
_testRoute.Clear();
_testRoute.Copy(route);
_testRoute.AddEnd(i);
Improver.Improve(_testRoute, false);
int dist = _testRoute.Length;
if (dist < score || (dist == score && val < bestVal))
{
best = i;
bestVal = val;
score = dist;
}
}
return(best);
}
public static Route CreateRandom(Graph graph, Random rand)
{
Route route = new Route(graph);
for (int i = 0; i < graph.Count; ++i)
{
route.AddEnd(rand.Next(i, graph.Count));
}
return(route);
}
public Route Search(Graph graph, bool printProgress = false)
{
if (printProgress) {
Console.ForegroundColor = ConsoleColor.Green;
Console.WriteLine("Starting a new {0} search with {1} thread{2}", GetType().Name,
Threads, Threads != 1 ? "s" : "");
Console.ForegroundColor = ConsoleColor.DarkGreen;
Console.WriteLine("Search will use {0} for each iteration", Searcher.GetType().Name);
Console.ForegroundColor = ConsoleColor.Green;
Console.Write("Progress: 0/{0} - 0", Attempts);
Console.ForegroundColor = ConsoleColor.White;
}
Route best = null;
int attempt = 0;
int exited = 0;
Func<bool> next = () => {
lock (this) {
if (attempt < Attempts) {
++attempt;
return true;
}
return false;
}
};
Func<bool> hasNext = () => {
lock (this)
return attempt < Attempts;
};
Func<bool> ended = () => {
lock (this)
return exited == Threads;
};
Action exit = () => {
lock (this)
++exited;
};
Action rejoin = () => {
lock (this)
--exited;
};
Func<bool> waitForEnd = () => {
exit();
while (!hasNext() && !ended())
Thread.Yield();
if (!ended()) {
rejoin();
return false;
} else
return true;
};
Action<Route> compare = (route) => {
lock (this) {
if (best == null || route.Length < best.Length) {
best = new Route(route);
attempt = 0;
if (BetterRouteFound != null)
BetterRouteFound(this, new BetterRouteFoundEventArgs(route));
} else if (attempt % (Attempts >> 4) == 0)
_rand = new Random();
if (printProgress) {
Console.CursorLeft = 10;
Console.Write("{0}/{1} - {2} ", attempt, Attempts, best.Length);
}
}
};
ThreadStart loop = () => {
Route route = new Route(graph);
for (; ; ) {
while (next()) {
route.Clear();
for (int i = 0; i < graph.Count; ++i) {
lock (_rand) route.AddEnd(_rand.Next(i, graph.Count));
Searcher.Improve(route);
}
compare(route);
}
if (waitForEnd())
break;
}
};
Thread[] workers = new Thread[Threads - 1];
for (int i = 0; i < workers.Length; ++i) {
workers[i] = new Thread(loop);
workers[i].Start();
}
loop();
if (printProgress) {
Console.ForegroundColor = ConsoleColor.Green;
Console.WriteLine("\n{0} search complete", GetType().Name);
Console.ForegroundColor = ConsoleColor.White;
}
return best;
}
public Route Search(Graph graph, bool printProgress = false)
{
if (printProgress)
{
Console.ForegroundColor = ConsoleColor.Green;
Console.WriteLine("Starting a new {0} search with {1} thread{2}", GetType().Name,
Threads, Threads != 1 ? "s" : "");
Console.ForegroundColor = ConsoleColor.DarkGreen;
Console.WriteLine("Search will use {0} for each iteration", Searcher.GetType().Name);
Console.ForegroundColor = ConsoleColor.Green;
Console.Write("Progress: 0/{0} - 0", Attempts);
Console.ForegroundColor = ConsoleColor.White;
}
Route best = null;
int attempt = 0;
int exited = 0;
Func <bool> next = () => {
lock (this) {
if (attempt < Attempts)
{
++attempt;
return(true);
}
return(false);
}
};
Func <bool> hasNext = () => {
lock (this)
return(attempt < Attempts);
};
Func <bool> ended = () => {
lock (this)
return(exited == Threads);
};
Action exit = () => {
lock (this)
++exited;
};
Action rejoin = () => {
lock (this)
--exited;
};
Func <bool> waitForEnd = () => {
exit();
while (!hasNext() && !ended())
{
Thread.Yield();
}
if (!ended())
{
rejoin();
return(false);
}
else
{
return(true);
}
};
Action <Route> compare = (route) => {
lock (this) {
if (best == null || route.Length < best.Length)
{
best = new Route(route);
attempt = 0;
if (BetterRouteFound != null)
{
BetterRouteFound(this, new BetterRouteFoundEventArgs(route));
}
}
else if (attempt % (Attempts >> 4) == 0)
{
_rand = new Random();
}
if (printProgress)
{
Console.CursorLeft = 10;
Console.Write("{0}/{1} - {2} ", attempt, Attempts, best.Length);
}
}
};
ThreadStart loop = () => {
Route route = new Route(graph);
for (; ;)
{
while (next())
{
route.Clear();
for (int i = 0; i < graph.Count; ++i)
{
lock (_rand) route.AddEnd(_rand.Next(i, graph.Count));
Searcher.Improve(route);
}
compare(route);
}
if (waitForEnd())
{
break;
}
}
};
Thread[] workers = new Thread[Threads - 1];
for (int i = 0; i < workers.Length; ++i)
{
workers[i] = new Thread(loop);
workers[i].Start();
}
loop();
if (printProgress)
{
Console.ForegroundColor = ConsoleColor.Green;
Console.WriteLine("\n{0} search complete", GetType().Name);
Console.ForegroundColor = ConsoleColor.White;
}
return(best);
}