finish lab4

Lab4/Lab4.csproj

@@ -0,0 +1,26 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <OutputType>Exe</OutputType>
+    <TargetFramework>net6.0</TargetFramework>
+    <ImplicitUsings>enable</ImplicitUsings>
+    <Nullable>enable</Nullable>
+    <PlatformTarget>x64</PlatformTarget>
+    <ProduceReferenceAssembly>False</ProduceReferenceAssembly>
+  </PropertyGroup>
+
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Debug|AnyCPU'">
+    <Deterministic>False</Deterministic>
+  </PropertyGroup>
+
+  <PropertyGroup Condition="'$(Configuration)|$(Platform)'=='Release|AnyCPU'">
+    <Deterministic>False</Deterministic>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <None Update="places.tsv">
+      <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
+    </None>
+  </ItemGroup>
+
+</Project>

Lab4/Program.cs

@@ -0,0 +1,197 @@
+using System.Diagnostics;
+using System.IO;
+
+namespace Lab4
+{
+    class Place
+    {
+        public string name;
+        public float x;
+        public float y;
+        public Place(string name, float x, float y)
+        {
+            this.name = name;
+            this.x = x;
+            this.y = y;
+        }
+    }
+
+    internal class Program
+    {
+        public static double GetDistance(Place A, Place B)
+        {
+            float dx = A.x - B.x;
+            float dy = A.y - B.y;
+            return Math.Sqrt(dx * dx + dy * dy);
+        }
+
+        public static double GetTravalCost(Place A, Place B)
+        {
+            return Math.Sqrt(GetDistance(A, B));
+        }
+
+        public static List<Place> ReadPlacesFromTSV(string filename)
+        {
+            List<Place> cities = new List<Place>();
+            foreach (var line in File.ReadLines(filename))
+            {
+                string[] parts = line.Split("\t");
+
+                string name = parts[0];
+                float x = float.Parse(parts[2]);
+                float y = float.Parse(parts[3]);
+                cities.Add(new Place(name, x, y));
+            }
+            return cities;
+        }
+
+        // Warning 'PickUnqiueNode' could get stuck in an infinite loop, if there are not enough places
+        public static int PickUnqiueNode(Random rand, List<int> path, int placesCount)
+        {
+            while (true)
+            {
+                int num = rand.Next(0, placesCount);
+                if (!path.Contains(num))
+                {
+                    return num;
+                }
+            }
+        }
+
+        public static List<int> GenerateRandomPath(Random rand, int size, int placesCount)
+        {
+            List<int> path = new List<int>(size);
+            for (int i = 0; i < size; i++)
+            {
+                path.Add(PickUnqiueNode(rand, path, placesCount));
+            }
+            return path;
+        }
+
+        public static double GetPathCost(List<int> path, List<Place> places)
+        {
+            double cost = 0;
+            for (int i = 0; i < path.Count-1; i++)
+            {
+                int from = path[i];
+                int to = path[i+1];
+                cost += GetTravalCost(places[from], places[to]);
+            }
+            cost += GetTravalCost(places[path.First()], places[path.Last()]);
+            return cost;
+        }
+
+        public static List<int> SplicePaths(Random rand, List<int> A, List<int> B)
+        {
+            Debug.Assert(A.Count == B.Count);
+
+            List<int> spliced = new List<int>(A.Count);
+            for (int i = 0; i < A.Count-1; i++)
+            {
+                spliced[i] = rand.Next(0, 2) == 0 ? A[i] : B[i];
+            }
+            return spliced;
+        }
+
+        public static void MutatePath(Random rand, List<int> path, float mutationPickUniqueChance, float mutationSwapChance, int placesCount)
+        {
+            for (int i = 0; i < path.Count; i++)
+            {
+                if (rand.NextSingle() < mutationPickUniqueChance) {
+                    path[i] = PickUnqiueNode(rand, path, placesCount);
+                }
+                if (rand.NextSingle() < mutationSwapChance) {
+                    int idx1 = rand.Next(0, path.Count);
+                    int idx2 = rand.Next(0, path.Count);
+
+                    (path[idx2], path[idx1]) = (path[idx1], path[idx2]);
+                }
+            }
+        }
+
+        static void Main(string[] args)
+        {
+            /*
+                Faile places_data.xlsx pateikta informacija apie lankytinas vietas (1 lentelė). Tikslas: kaip galima pigesnio maršruto sudarymas kai,
+                
+                * priimama, kad kelionės tarp vietų kaina lygi kvadratinei šakniai iš kelionės atstumo;
+                * kelionės pradžios ir pabaigos vieta sutampa (su grįžimu atgal);
+                * ta pati vieta negali būti aplankyta daugiau nei vieną;
+                * Reikia aplankyti bet kurias 150 vietų iš pateikto sąrašo.
+            */
+
+            int pathLength = 150;
+            int batchSize = 50;
+            int timeLimitMs = 60 * 1000;
+            float mutationPickUniqueChance = 0.05f;
+            float mutationSwapChance = 0.05f;
+
+            int seed = (int)DateTime.Now.Ticks;
+            Random rand = new Random(seed);
+
+            var places = ReadPlacesFromTSV("places.tsv");
+            
+            var bestPaths = new SortedList<double, List<int>>();
+            for (int i = 0; i < batchSize; i++)
+            {
+                var path = GenerateRandomPath(rand, pathLength, places.Count);
+                var cost = GetPathCost(path, places);
+                bestPaths.Add(cost, path);
+            }
+
+            var stopwatch = new Stopwatch();
+            int iteration = 0;
+            stopwatch.Start();
+            while (stopwatch.ElapsedMilliseconds < timeLimitMs)
+            {
+                double bestScore = bestPaths.First().Key;
+                double worstScore = bestPaths.Last().Key;
+
+                if (iteration % 200 == 0)
+                {
+                    //Console.WriteLine("At {0}, best '{1}', worst '{2}'", iteration, bestScore, worstScore);
+                }
+
+                var removedPaths = new List<double>();
+                var parentPool = new List<List<int>>();
+                foreach (var entry in bestPaths)
+                {
+                    double probability = (entry.Key - bestScore) / (worstScore - bestScore);
+                    if (rand.NextSingle() >= probability) {
+                        parentPool.Add(entry.Value);
+                    } else {
+                        removedPaths.Add(entry.Key);
+                    }
+                }
+
+                foreach (var key in removedPaths)
+                {
+                    bestPaths.Remove(key);
+                }
+
+                while (batchSize > bestPaths.Count)
+                {
+                    var parentIdx = rand.Next(0, parentPool.Count);
+                    var parent = parentPool[parentIdx];
+                    var child = new List<int>(parent);
+                    MutatePath(rand, child, mutationPickUniqueChance, mutationSwapChance, places.Count);
+                    var cost = GetPathCost(child, places);
+                    if (!bestPaths.ContainsKey(cost)) {
+                        bestPaths.Add(cost, child);
+                    }
+                }
+                
+                iteration++;
+            }
+            stopwatch.Stop();
+
+            Console.WriteLine("Best after {0} iterations is {1}", iteration, bestPaths.First().Key);
+            Console.WriteLine("Time taken: {0}ms", stopwatch.ElapsedMilliseconds);
+            Console.WriteLine("Seed: {0}", seed);
+
+            // Best after 484012 iterations is 30826.444176719036
+            // Time taken: 60000ms
+            // Seed: -1477536140
+        }
+    }
+}

Labs.sln

@@ -7,7 +7,9 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Lab1", "Lab1\Lab1.csproj",
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Lab2", "Lab2\Lab2.csproj", "{6AF5D775-08B9-4D4F-9E2E-116C551D0581}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Lab3", "Lab3\Lab3.csproj", "{C3128C1D-C1F7-476A-808F-1A3FE5E848FA}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Lab3", "Lab3\Lab3.csproj", "{C3128C1D-C1F7-476A-808F-1A3FE5E848FA}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Lab4", "Lab4\Lab4.csproj", "{6C74D00D-C10B-4249-99F7-E2CAD924D96B}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
@@ -27,6 +29,10 @@ Global
 		{C3128C1D-C1F7-476A-808F-1A3FE5E848FA}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{C3128C1D-C1F7-476A-808F-1A3FE5E848FA}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{C3128C1D-C1F7-476A-808F-1A3FE5E848FA}.Release|Any CPU.Build.0 = Release|Any CPU
+		{6C74D00D-C10B-4249-99F7-E2CAD924D96B}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{6C74D00D-C10B-4249-99F7-E2CAD924D96B}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{6C74D00D-C10B-4249-99F7-E2CAD924D96B}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{6C74D00D-C10B-4249-99F7-E2CAD924D96B}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE