/// <summary>
/// Create an exact solution using input data from the Console
/// </summary>
private static void RunExactConsole()
{
Node[] inputAsNodes = IO.ReadInputAsNodes(CENTER_RESEMBLANCE_CAP, ARTICULATION_POINT_MINIMUM);
RecursiveSplit recSplit = new RecursiveSplit(inputAsNodes);
RecursiveTree <Node> recTree = recSplit.GetBestTree();
string output = recTree.ToString();
Console.Write(output);
}
/// <summary>
/// Runs either the exact version of RecursiveSplit. Does not use any form of local search
/// </summary>
/// <param name="fileName">The name of the file to be used as input (without extension)</param>
private static void RunExact(string fileName)
{
Console.WriteLine($"Starting file {fileName}...");
Node[] inputAsNodes = IO.ReadInputAsNodes($"..\\..\\..\\..\\..\\Testcases\\{fileName}.gr", CENTER_RESEMBLANCE_CAP, ARTICULATION_POINT_MINIMUM);
RecursiveSplit recSplit = new RecursiveSplit(inputAsNodes);
RecursiveTree <Node> recTree;
recTree = recSplit.GetBestTree();
string output = recTree.ToString();
using (StreamWriter sw = new StreamWriter($"..\\..\\..\\..\\..\\Results\\{fileName}.tree", false))
{
sw.Write(output);
}
Console.WriteLine($"Tree found with depth {recTree.Depth}.");
Console.WriteLine();
}
/// <summary>
/// Execute the program using simulated annealing
/// </summary>
/// <param name="fileName">The name of the file to be run, or empty if the console is used</param>
/// <param name="console">Whether input form the console is used. If so, the program runs in quiet mode</param>
private static void SimulatedAnnealing(string fileName = "", bool console = true)
{
if (!console)
{
Console.WriteLine($"Starting file {fileName}...");
}
// The stopwatch keeps track of the total running time of the program
stopwatchSingleRun.Start();
// Read the input, depending on whether the console is used a file is being read or console input
Node[] inputAsNodes;
if (!console)
{
inputAsNodes = IO.ReadInputAsNodes($"..\\..\\..\\..\\..\\Testcases\\{fileName}.gr", CENTER_RESEMBLANCE_CAP, ARTICULATION_POINT_MINIMUM);
}
else
{
inputAsNodes = IO.ReadInputAsNodes(CENTER_RESEMBLANCE_CAP, ARTICULATION_POINT_MINIMUM);
}
allNodes = inputAsNodes;
// Create instances for the simunlated annealing and recursivesplit classes
SimulatedAnnealing <State <RecursiveTree <Node> >, RecursiveTree <Node> > simulatedAnnealing =
new SimulatedAnnealing <State <RecursiveTree <Node> >, RecursiveTree <Node> >(random, START_TEMP, RESET_TEMPERATURE_THRESHOLD, TEMP_MULTIPLIER, MULTIPLY_TEMP_PER_ITERATIONS, stopwatchSingleRun, MAX_TIME_TOTAL_SECONDS);
RecursiveSplit recursiveSplit = new RecursiveSplit(inputAsNodes);
// Find an initial solution where all nodes are in a single line
RecursiveTreeState heurInitState = new RecursiveTreeState(BaseSolutionGenerator.LineRecursiveTree(ref allRecTreeNodes, allNodes), random, allRecTreeNodes);
bestStateSoFar = heurInitState.Data.ToString();
if (!console)
{
Console.WriteLine($"Line found with depth {heurInitState.Data.Root.Depth}.");
}
initialSolutionsTimer.Start();
RecursiveTree <Node> bestTree = null;
// Find an initial solution using the RecursiveSplit using a fast but bad heuristic
if (allNodes.Length <= FASTER_HEURISTIC_CAP)
{
double maxTime = MAX_TIME_INITIAL_SOLUTIONS_SECONDS;
if (allNodes.Length > INDEPENDENT_SET_CAP)
{
if (allNodes.Length > FAST_HEURISTIC_CAP)
{
maxTime *= 3;
}
else
{
maxTime *= 1.5;
}
}
else if (allNodes.Length > FAST_HEURISTIC_CAP)
{
maxTime *= 1.5;
}
bestTree = recursiveSplit.GetHeuristicTree(initialSolutionsTimer, maxTime, true);
if (!console)
{
Console.WriteLine($"Fastest heuristic tree found with depth {bestTree.Depth}.");
}
}
// Find an initial solution using the RecursiveSplit using a decent but pretty slow heuristic
if (allNodes.Length <= FAST_HEURISTIC_CAP)
{
double maxTime = MAX_TIME_INITIAL_SOLUTIONS_SECONDS;
if (allNodes.Length > INDEPENDENT_SET_CAP)
{
maxTime *= 3;
}
else if (allNodes.Length > FASTER_HEURISTIC_CAP)
{
maxTime *= 1.5;
}
else
{
maxTime *= 2;
}
RecursiveTree <Node> treeFromFastHeuristic = recursiveSplit.GetHeuristicTree(initialSolutionsTimer, maxTime, false);
if (bestTree == null || treeFromFastHeuristic.Depth < bestTree.Depth)
{
bestTree = treeFromFastHeuristic;
}
if (!console)
{
Console.WriteLine($"Fast heuristic tree found with depth {treeFromFastHeuristic.Depth}.");
}
}
// If the problem instance is small enough, we would like to try to find an initial solution using independent sets
if (allNodes.Length <= INDEPENDENT_SET_CAP)
{
double maxTime = MAX_TIME_INITIAL_SOLUTIONS_SECONDS * 3;
RecursiveTree <Node> treeFromIndependentSet = IndependentSet.TreeFromIndependentSets(allNodes, initialSolutionsTimer, maxTime);
if (bestTree == null || treeFromIndependentSet.Depth < bestTree.Depth)
{
bestTree = treeFromIndependentSet;
}
if (!console)
{
Console.WriteLine($"Independent set tree found with depth {treeFromIndependentSet.Depth}.");
}
}
// Recreate the tree and save the best found initial solution as the initial solution for simulated annealing
initialSolutionsTimer.Reset();
if (bestTree != null)
{
bestStateSoFar = bestTree.ToString();
RecreateTree(bestStateSoFar);
heurInitState = new RecursiveTreeState(allRecTreeNodes[0].Root, random, allRecTreeNodes);
}
if (allNodes.Length <= SIMULATED_ANNEALING_CAP)
{
simulatedAnnealing.Search(heurInitState, ref bestStateSoFar);
}
// If the input from the console is not used, write the output to a file, otherwise write it back to the console
if (!console)
{
using (StreamWriter sw = new StreamWriter($"..\\..\\..\\..\\..\\Results\\{fileName}.tree", false))
{
sw.Write(bestStateSoFar);
}
}
else
{
Console.Write(bestStateSoFar);
}
// Print the result and total time thus far
if (!console)
{
// Stop the total of this problem instace
stopwatchSingleRun.Stop();
Console.WriteLine($"Tree found with depth {bestStateSoFar.Split('\n')[0]} in {stopwatchSingleRun.Elapsed} seconds. (Total time: {allRunsTotalStopwatch.Elapsed})");
Console.WriteLine();
}
// Reset the stopwatch for the next time the program is run
stopwatchSingleRun.Reset();
}