// "Dumb mutation" - just swap some elements
private void mutateDumb(TSPSolution initial)
{
PermutationStandard current = new PermutationStandard(initial);
current.swap(rnd.Next(current.size), rnd.Next(current.size));
current.applyToTSPSolution(initial);
}
//returns number of updates to BSSF made during the exploration
private void explore(SearchSpace current, PriorityQ q)
{
List <int> citiesRemaining = current.CitiesRemaining;
bool leaf = true;
//O()
foreach (int city in citiesRemaining)
{
leaf = false;
SearchSpace child = new SearchSpace(current, city);//O(n^2)
statesCreated++;
if (child.Bound < costOfBssf())
{
q.Insert(child);
}
else
{
statesPruned++;
}
}
if (leaf)
{
TSPSolution possibleSoln = new TSPSolution(current.Route, Cities);
if (possibleSoln.costOfRoute() < costOfBssf())
{
bssf = possibleSoln;
solutionsFound++;
}
}
}
// performs local search (switches two points in the solution) and searches for better result
private Boolean updateBssf(int[] route)
{
Boolean result = false;
for (int i = 0; i < _size; i++)
{
for (int j = i + 1; j < _size; j++)
{
int[] child = new int[route.Length];
Array.Copy(route, child, _size);
child[i] = route[j]; //switch two points
child[j] = route[i];
// check if child is a new local/global max
if (costOfRoute(child) < costOfRoute(myBssf))
{
myBssf = child;
if (costOfRoute(myBssf) < bssf.costOfRoute())
{
bssf = bssfFromIntArray(new ArrayList(myBssf));
}
result = true;
}
}
}
return(result);
}
public TSPSolution solve(TSPInput input)
{
TSPSolution best = null;
for (int r = 0; r < 5; ++r)
{
Console.WriteLine($@"== RUN:{r} ==");
population.Clear();
for (int i = 0; i < PopulationSize; ++i)
{
population.Add(getRandomSolution(input));
}
run();
var tmp = GetBest();
Console.WriteLine($@"Distance: {tmp.totalDistance}");
if (best == null || tmp.totalDistance < best.totalDistance)
{
best = tmp;
}
}
visualizer.draw(best);
return(best);
}
public void solveAndShow()
{
solution = solver.solve(inp);
solution.computeDistance();
Length_label.Text = solution.totalDistance.ToString();
vis.draw(solution);
}
/////////////////////////////////////////////////////////////////////////////////////////////
// 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];
// TODO: Add your implementation for a greedy solver here.
Stopwatch timer = new Stopwatch();
timer.Start();
Route = new ArrayList();
greedySolveSub();
// At this point, we have all the cities.
// We have a problem though. What if the last city does not go back to the first one???
while (((City)Route[Route.Count - 1]).costToGetTo((City)Route[0]) == Double.PositiveInfinity)
{
greedySolveSub();
}
bssf = new TSPSolution(Route);
timer.Stop();
results[COST] = costOfBssf().ToString(); // load results into array here, replacing these dummy values
results[TIME] = timer.Elapsed.ToString();
results[COUNT] = "1";
return(results);
}
// Reset the problem instance
private void resetData()
{
cities = new City[size];
bssf = null;
if (mode == HardMode.Modes.Easy)
{
for (int i = 0; i < size; i++)
{
cities[i] = new City(rnd.NextDouble(), rnd.NextDouble());
}
}
else // Medium and hard
{
for (int i = 0; i < size; i++)
{
cities[i] = new City(rnd.NextDouble(), rnd.NextDouble(), rnd.NextDouble() * City.MAX_ELEVATION);
}
}
HardMode mm = new HardMode(this.mode, this.rnd, cities);
if (mode == HardMode.Modes.Hard)
{
int edgesToRemove = (int)(size * FRACTION_OF_PATHS_TO_REMOVE);
mm.removePaths(edgesToRemove);
}
City.setModeManager(mm);
}
// "Smart mutation" - try to swap and improve the distance
private void mutateSmart(TSPSolution initial)
{
PermutationStandard current = new PermutationStandard(initial);
var start = current.eval();
var best = start;
var bestX = 0;
var bestY = 0;
for (int i = 0; i < current.perm.Length; ++i)
{
for (int j = 0; j < current.perm.Length; ++j)
{
current.swap(i, j);
var temp = current.eval();
current.swap(j, i);
if (temp < best)
{
best = temp;
bestX = i;
bestY = j;
}
}
}
if (best < start)
{
current.swap(bestX, bestY);
current.applyToTSPSolution(initial);
}
}
/////////////////////////////////////////////////////////////////////////////////////////////
// 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>
// O(n^3) - goes through each city for each city, with each city as a root node - n*n*n
public string[] greedySolveProblem()
{
// initialize the vairables
int count = 0;
string[] results = new string[3];
int[] perm = new int[Cities.Length];
Route = new ArrayList();
double currSol = Double.PositiveInfinity;
Stopwatch timer = new Stopwatch();
timer.Start();
// for each city as a starting node, find the best greedy solution
// greedy for one node - O(n^2), doing that for each city as a root:
// O(n^3)
for (int i = 0; i < Cities.Length; i++)
{
ArrayList newRoute = findGreedyPath(i);
TSPSolution greedyRoute = new TSPSolution(newRoute);
double temp = costOfBssf();
if (temp < currSol)
{
currSol = temp;
Route = newRoute;
bssf = greedyRoute;
}
}
timer.Stop();
results[COST] = costOfBssf().ToString(); // load results array
results[TIME] = timer.Elapsed.ToString();
results[COUNT] = count.ToString();
return(results);
}
public TSPSolution solve(TSPInput input)
{
GreedySolver s = new GreedySolver();
best = s.solve(input).computeDistance() + 1;
bestSolution = new int[input.nodesCount];
List <int> current = new List <int>();
current.Add(0);
List <int> remaining = new List <int>();
for (int i = 1; i < input.nodesCount; i++)
{
remaining.Add(i);
}
trySolve(input, current, remaining, 0);
TSPSolution result = new TSPSolution(input);
for (int i = 0; i < input.nodesCount - 1; i++)
{
result.setSuccessor(bestSolution[i], bestSolution[i + 1]);
}
result.setSuccessor(bestSolution[input.nodesCount - 1], 0);
return(result);
}
public TSPSolution solve(TSPInput input)
{
Console.WriteLine("Hill climbing started");
current = initialize(input);
currentBest = current.convertToTSPSol();
visualizer.draw(currentBest);
stop = false;
int steps = 0;
while (!stop)
{
steps++;
goOneStep();
if (steps % 10 == 0)
{
currentBest = current.convertToTSPSol();
visualizer.draw(currentBest);
Console.WriteLine("Steps: " + steps + " Best distance: " + currentBest.totalDistance);
}
}
Console.WriteLine("Search ended");
currentBest = current.convertToTSPSol();
visualizer.draw(currentBest);
Console.WriteLine("Steps: " + steps + " Best distance: " + currentBest.totalDistance);
return(currentBest);
}
public void draw(TSPSolution sol, bool clear = true)
{
draw(sol.inp, clear);
int j = 0, previous = 0;
for (int i = 0; i < sol.inp.nodesCount; i++)
{
TSPPoint first = sol.inp.getPoint(j), second = sol.inp.getPoint(sol.getSuccessor(j, previous));
Pen pen = Pens.BlueViolet;
for (int k = 0; k < sol.inp.nodesCount; k++)
{
if (Edge.isCrossing(first, second, sol.inp.getPoint(k), sol.inp.getPoint(sol.getSuccessor(k))) &&
Edge.isCrossing(sol.inp.getPoint(k), sol.inp.getPoint(sol.getSuccessor(k)), first, second))
{
pen = Pens.Red;
break;
}
}
//TODO vybarvit cervene ty co se krizi - hotovo
g.DrawLine(pen, (float)(first.x * xStretch + nodeSize / 2), (float)(first.y * yStretch + nodeSize / 2),
(float)(second.x * xStretch + nodeSize / 2), (float)(second.y * yStretch + nodeSize / 2));
int pom = j;
j = sol.getSuccessor(j, previous);
previous = pom;
}
screen.Refresh();
}
/// <summary>
/// Reset the problem instance.
/// </summary>
private void resetData()
{
Cities = new City[_size];
Route = new List <int>(_size);
bssf = null;
if (_mode == HardMode.Modes.Easy)
{
for (int i = 0; i < _size; i++)
{
Cities[i] = new City(rnd.NextDouble(), rnd.NextDouble());
}
}
else // Medium and hard
{
for (int i = 0; i < _size; i++)
{
Cities[i] = new City(rnd.NextDouble(), rnd.NextDouble(), rnd.NextDouble() * City.MAX_ELEVATION);
}
}
HardMode mm = new HardMode(this._mode, this.rnd, Cities);
if (_mode == HardMode.Modes.Hard)
{
int edgesToRemove = (int)(_size * FRACTION_OF_PATHS_TO_REMOVE);
mm.removePaths(edgesToRemove);
}
City.setModeManager(mm);
cityBrushStyle = new SolidBrush(Color.Black);
cityBrushStartStyle = new SolidBrush(Color.Red);
routePenStyle = new Pen(Color.Blue, 1);
routePenStyle.DashStyle = System.Drawing.Drawing2D.DashStyle.Solid;
}
public string[] greedySolveProblem()
{
string[] results = new string[3];
var watch = System.Diagnostics.Stopwatch.StartNew();
for (int i = 0; i < Cities.Length; i++)
{
TSPSolution temp = greedySolveProblem(i);
double tempLength = temp.costOfRoute();
double bssfLength = costOfBssf();
if (bssf == null)
{
bssf = temp;
}
else
{
if (temp.costOfRoute() < costOfBssf())
{
bssf = temp;
}
}
}
results[COST] = bssf.costOfRoute().ToString(); // load results into array here, replacing these dummy values
results[TIME] = watch.Elapsed.ToString();
results[COUNT] = "1";
return(results);
}
//gets BSSF using random cycle
private void defaultGetBSSF()
{
int i, swap, temp, count = 0;
int[] perm = new int[Cities.Length];
Route = new List <int>();
Random rnd = new Random();
do
{
for (i = 0; i < perm.Length; i++) // create a random permutation template
{
perm[i] = i;
}
for (i = 0; i < perm.Length; i++)
{
swap = i;
while (swap == i)
{
swap = rnd.Next(0, Cities.Length);
}
temp = perm[i];
perm[i] = perm[swap];
perm[swap] = temp;
}
Route.Clear();
for (i = 0; i < Cities.Length; i++) // Now build the route using the random permutation
{
Route.Add(perm[i]);
}
bssf = new TSPSolution(Route, Cities);
count++;
} while (costOfBssf() == double.PositiveInfinity); // until a valid route is found
}
public string[] fancySolveProblem()
{
string[] results = new string[3];
Route = new ArrayList();
GeneticSolver geneticSolver = new GeneticSolver(ref Cities);
geneticSolver.solve();
ArrayList newRoute = new ArrayList();
byte[] gene = geneticSolver.getBestRoute();
//Console.WriteLine(string.Join(",", gene));
for (int i = 0; i < gene.Length; i++)
{
newRoute.Add(Cities[gene[i]]);
}
TSPSolution solution = new TSPSolution(newRoute);
bssf = solution;
Route = newRoute;
//results[COST] = geneticSolver.getCost();
results[COST] = costOfBssf().ToString();
results[TIME] = geneticSolver.getTime();
results[COUNT] = geneticSolver.getCount();
return(results);
}
public string[] fancySolveProblem()
{
string[] results = new string[3];
// implement simulated annealing
string[] origResults = defaultSolveProblem();
double origCost = Convert.ToDouble(origResults[COST]);
//City start = (City)Route[0];
double bestCostSoFar = origCost;
double tempBestCost = origCost;
int temperature = 10000;
while (temperature != 0)
{
Random rand = new Random();
int random = rand.Next(0, Cities.Length);
int random2 = rand.Next(0, Cities.Length);
City one = (City)Route[random];
City two = (City)Route[random2];
ArrayList copyRoute = new ArrayList();
for (int i = 0; i < Route.Count; i++)
{
if (i == random)
{
copyRoute.Add(two);
}
else if (i == random2)
{
copyRoute.Add(one);
}
else
{
copyRoute.Add(Route[i]);
}
}
TSPSolution temp = new TSPSolution(copyRoute);
double var = temp.costOfRoute();
if (temp.costOfRoute() != Double.PositiveInfinity)
{
if (isAcceptable(tempBestCost, temp.costOfRoute(), temperature))
{
Route = copyRoute;
tempBestCost = temp.costOfRoute();
if (tempBestCost < bestCostSoFar)
{
bestCostSoFar = tempBestCost;
bssf = temp;
}
}
}
temperature -= 5;
}
results[COST] = bssf.costOfRoute().ToString(); // load results into array here, replacing these dummy values
results[TIME] = "-1";
results[Count] = "-1";
return(results);
}
private TSPSolution solve(TSPInput input, bool hasEdge = false, int startNode = 0, int endNode = 0)
{
TSPSolution result = null;
if (hasEdge)
{
result = new TSPSolutionPath(input, startNode, endNode);
}
else
{
result = new TSPSolution(input);
}
succ = new List <List <int> >();
edge predefinedEdge = default;
edgesUsed = 0;
List <edge> edges = new List <edge>();
for (int i = 0; i < input.nodesCount; i++)
{
succ.Add(new List <int>());
for (int j = 0; j < i; j++)
{
edge ed = new edge(i, j, input.getDistance(i, j));
if (hasEdge && (startNode == i && endNode == j) || (startNode == j && endNode == i))
{
predefinedEdge = ed;
}
else
{
edges.Add(ed);
}
}
}
if (hasEdge)
{
addToSolution(predefinedEdge);
}
edges.Sort((a, b) => (int)(a.distance - b.distance));
int index = -1;
while (edgesUsed < input.nodesCount)
{
index++;
edge e = edges[index];
if (succ[e.node1].Count >= 2 || succ[e.node2].Count >= 2)
{
continue;
}
if (createsCycle(e) && edgesUsed != input.nodesCount - 1)
{
continue;
}
addToSolution(e);
}
addEdgesToResult(result);
return(result);
}
public void applyToTSPSolution(TSPSolution sol)
{
for (int i = 0; i < size - 1; i++)
{
sol.setSuccessor(perm[i], perm[i + 1]);
}
sol.setSuccessor(perm[size - 1], perm[0]);
}
public string[] fancySolveProblem()
{
string[] results = new string[3];
//set initial bssf
initialBssf = true;
greedySolveProblem();
//defaultSolveProblem();
Console.WriteLine("---------------");
Console.WriteLine("Initial bssf cost: " + bssf.costOfRoute().ToString());
Stopwatch timer = new Stopwatch();
// TODO bssf = output of greedy algorithm
int numCities = Cities.Length;
int solutions = 0;
bool improved = true;
timer.Start();
// while(bestChild.route < bssf.route
while (improved)
{
long time = timer.ElapsedMilliseconds;
if (time > time_limit)
{
Console.WriteLine("Fancy timed out");
break;
}
improved = false;
for (int i = 0; i < numCities - 1; i++)
{
for (int k = 0; k < numCities - 1; k++)
{
if (i == k)
{
continue;
}
// swap i and k
TSPSolution checkSolution = swap(i, k);
solutions++;
double cost = checkSolution.costOfRoute();
// check to see if it's a better solution than best child
if (cost < bssf.costOfRoute())
{
// if so, set best child be a solutionn
bssf = checkSolution;
improved = true;
}
//if didn't improve, found local optimum
}
}
}
Console.WriteLine("K-opt cost: " + bssf.costOfRoute().ToString());
Console.WriteLine("Number of solutions: " + solutions);
timer.Stop();
results[COST] = bssf.costOfRoute().ToString(); // load results into array here, replacing these dummy values
results[TIME] = timer.Elapsed.TotalSeconds.ToString();
results[COUNT] = solutions.ToString();
return(results);
}
public PermutationStandard(TSPSolution sol) : this(sol.inp)
{
perm[0] = 0;
perm[1] = sol.getSuccessor(perm[0]);
for (int i = 1; i < size - 1; i++)
{
perm[i + 1] = sol.getSuccessor(perm[i], perm[i - 1]);
}
}
public string[] fancySolveProblem()
{
string[] results = new string[3];
Stopwatch timer = new Stopwatch();
int i, swap, temp, count = 0;
int[] perm = new int[Cities.Length];
Route = new ArrayList();
Random rnd = new Random();
timer.Start();
const int ITERATIONS = 1000000;
for (int iteration = 0; iteration < ITERATIONS; ++iteration)
{
do
{
for (i = 0; i < perm.Length; i++) // create a random permutation template
{
perm[i] = i;
}
for (i = 0; i < perm.Length; i++)
{
swap = i;
while (swap == i)
{
swap = rnd.Next(0, Cities.Length);
}
temp = perm[i];
perm[i] = perm[swap];
perm[swap] = temp;
}
Route.Clear();
for (i = 0; i < Cities.Length; i++) // Now build the route using the random permutation
{
Route.Add(Cities[perm[i]]);
}
TSPSolution solution = new TSPSolution(Route);
if (solution.costOfRoute() < costOfBssf() || costOfBssf() == -1)
{
bssf = solution;
}
count++;
} while (costOfBssf() == double.PositiveInfinity); // until a valid route is found
}
timer.Stop();
results[COST] = costOfBssf().ToString(); // load results array
results[TIME] = timer.Elapsed.ToString();
results[COUNT] = count.ToString();
return(results);
}
/////////////////////////////////////////////////////////////////////////////////////////////
// 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];
GreedySolver greedy = new GreedySolver(Cities, bssf, results);
bssf = greedy.Solve();
return(results);
}
private TSPSolution bssfFromIntArray(ArrayList intArray)
{
Route = new ArrayList();
foreach (int i in intArray)
{
Route.Add(Cities[i]);
}
bssf = new TSPSolution(Route);
return(bssf);
}
private void initializeBSSF()
{
Route = new ArrayList();
for (int x = 0; x < Cities.Length; x++)
{
Route.Add(Cities[x]);
}
Route.Add(Cities[0]);
bssf = new TSPSolution(Route);
}
private bool isShorterToSwap(Edge e1, Edge e2, TSPSolution sol, bool firstChoice)
{
if (firstChoice)
{
return(sol.inp.getDistance(e1.from, e2.from) + sol.inp.getDistance(e1.to, e2.to)
< e1.weight + e2.weight);
}
return(sol.inp.getDistance(e1.from, e2.to) + sol.inp.getDistance(e1.to, e2.from)
< e1.weight + e2.weight);
}
public static TSPSolution GetNew(TSPSolution parent1, TSPSolution parent2)
{
PermutationStandard ps1 = new PermutationStandard(parent1);
PermutationStandard ps2 = new PermutationStandard(parent2);
PermutationStandard tmp = new PermutationStandard(parent2);
// Keep track of elements, which have not been moved yet
List <bool> moved = new List <bool>(tmp.size);
for (int i = 0; i < tmp.size; ++i)
{
moved.Add(false);
}
// starting point of the cycle - first unmoved element
moved[0] = true;
while (moved.Contains(false))
{
Cycle cycle = new Cycle();
int start = moved.IndexOf(false);
// find the cycle
while (!cycle.IsComplete())
{
int through = ps2.perm[start];
int to = 0;
for (int i = 0; i < ps1.perm.Length; ++i)
{
if (ps1.perm[i] == through)
{
to = i;
}
}
cycle.Add(start, to);
start = to;
}
// elements from ps1 where the cycle goes
foreach (var startingPoint in cycle.GetStartingPoints())
{
tmp.perm[startingPoint] = ps1.perm[startingPoint];
moved[startingPoint] = true;
}
// swap ps1 and ps2
var swap = ps1;
ps1 = ps2;
ps2 = swap;
}
return(tmp.convertToTSPSol());
}
public TSPSolution solve(TSPInput input)
{
computeSpanningTree(input);
TSPSolution result = new TSPSolution(input);
visited.Clear();
labelTreePreOrder(0, result);
result.setSuccessor(lastNodeLabeled, 0);
return(result);
//return null;
}
public TSPSolution convertToTSPSol()
{
TSPSolution sol = new TSPSolution(input);
for (int i = 0; i < size - 1; i++)
{
sol.setSuccessor(perm[i], perm[i + 1]);
}
sol.setSuccessor(perm[size - 1], perm[0]);
return(sol);
}
/// <summary>
/// solve the problem. This is the entry point for the solver when
/// the run button is clicked
/// right now it just picks a simple solution.
/// </summary>
public void solveProblem()
{
IDictionary <Tuple <City, City>, double> EdgeRatings = RateEdges();
Route = FindRoute(EdgeRatings);
bssf = new TSPSolution(Route);
// update the cost of the tour.
Program.MainForm.tbCostOfTour.Text = " " + bssf.costOfRoute();
// do a refresh.
Program.MainForm.Invalidate();
}
