Extract common search logic to base classes

ApmeM · Jul 20, 2024 · 9508aea · 9508aea
1 parent b4dffcf
commit 9508aea
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Showing 7 changed files with 166 additions and 357 deletions.
diff --git a/BrainAI.Benchmarks/Program.cs b/BrainAI.Benchmarks/Program.cs
@@ -107,8 +107,9 @@ public void Pathfinding()
         var end = this.GraphType == GraphTypes.Grid ? new Point((int)MapSize - 1, (int)MapSize - 1) : new Point((int)MapSize - 5, (int)MapSize - 4);
         for (var i = 0; i < (int)this.RunsCount; i++)
         {
-            var pathData = this.pathfinder!.Search(start, end);
-            if (pathData == null)
+            this.pathfinder!.Search(start, end);
+            var pathData = this.pathfinder!.ResultPath;
+            if (pathData.Count == 0)
             {
                 throw new System.Exception("Path not found.");
             }

diff --git a/BrainAI/Pathfinding/AStar/AStarPathfinder.cs b/BrainAI/Pathfinding/AStar/AStarPathfinder.cs
@@ -1,107 +1,17 @@
 namespace BrainAI.Pathfinding
 {
     using System;
-    using System.Collections.Generic;
 
-    public class AStarPathfinder<T> : IPathfinder<T>
+    public class AStarPathfinder<T> : Pathfinder<T>
     {
-        public Dictionary<T, T> VisitedNodes { get; } = new Dictionary<T, T>();
-
-        public List<T> ResultPath { get; set; } = new List<T>();
-
-        private readonly HashSet<T> tmpGoals = new HashSet<T>();
-
-        private T searchStart;
-
         private readonly IAstarGraph<T> graph;
 
-        private readonly Dictionary<T, int> costSoFar = new Dictionary<T, int>();
-
-        private readonly PriorityQueue<(int, T), int> frontier = new PriorityQueue<(int, T), int>();
-
-        private List<T> neighbours = new List<T>();
-
         public AStarPathfinder(IAstarGraph<T> graph)
         {
             this.graph = graph;
         }
 
-        public void Search(T start, T goal)
-        {
-            this.PrepareSearch();
-            this.StartNewSearch(start);
-
-            tmpGoals.Add(goal);
-
-            ContinueSearch();
-        }
-
-        public void Search(T start, HashSet<T> goals)
-        {
-            this.PrepareSearch();
-            this.StartNewSearch(start);
-
-            foreach (var goal in goals)
-            {
-                this.tmpGoals.Add(goal);
-            }
-
-            ContinueSearch();
-        }
-
-        public void Search(T start, int additionalDepth)
-        {
-            this.PrepareSearch();
-            this.StartNewSearch(start);
-
-            InternalSearch(additionalDepth);
-        }
-
-        public void Search(T start, T goal, int additionalDepth)
-        {
-            this.PrepareSearch();
-            this.StartNewSearch(start);
-
-            this.tmpGoals.Add(goal);
-
-            ContinueSearch(additionalDepth);
-        }
-
-        public void Search(T start, HashSet<T> goals, int additionalDepth)
-        {
-            this.PrepareSearch();
-            this.StartNewSearch(start);
-
-            foreach (var goal in goals)
-            {
-                this.tmpGoals.Add(goal);
-            }
-
-            ContinueSearch(additionalDepth);
-        }
-
-        public void ContinueSearch()
-        {
-            this.ResultPath.Clear();
-            if (tmpGoals.Count == 0)
-            {
-                return;
-            }
-
-            ContinueSearch(int.MaxValue);
-        }
-
-        public void ContinueSearch(int additionalDepth)
-        {
-            this.ResultPath.Clear();
-            var (target, isFound) = InternalSearch(additionalDepth);
-            if (isFound)
-            {
-                PathConstructor.RecontructPath(VisitedNodes, searchStart, target, this.ResultPath);
-            }
-        }
-
-        private ValueTuple<T, bool> InternalSearch(int additionalDepth)
+        internal override ValueTuple<T, bool> InternalSearch(int additionalDepth)
         {
             var goal = this.GetFirstGoal();
 
@@ -145,22 +55,5 @@ private T GetFirstGoal()
 
             throw new Exception("No goals found.");
         }
-
-        private void PrepareSearch()
-        {
-            this.ResultPath.Clear();
-            this.frontier.Clear();
-            this.VisitedNodes.Clear();
-            this.tmpGoals.Clear();
-            this.costSoFar.Clear();
-        }
-
-        private void StartNewSearch(T start)
-        {
-            this.searchStart = start;
-            this.VisitedNodes.Add(start, start);
-            this.frontier.Enqueue(new ValueTuple<int, T>(0, start), 0);
-            this.costSoFar[start] = 0;
-        }
     }
 }
diff --git a/BrainAI/Pathfinding/BreadthFirst/BreadthFirstPathfinder.cs b/BrainAI/Pathfinding/BreadthFirst/BreadthFirstPathfinder.cs
@@ -1,149 +1,50 @@
 namespace BrainAI.Pathfinding
 {
     using System;
-    using System.Collections.Generic;
 
     /// <summary>
     /// Calculates paths given an IUnweightedGraph and start/goal positions
     /// </summary>
-    public class BreadthFirstPathfinder<T> : IPathfinder<T>, ICoveragePathfinder<T>
+    public class BreadthFirstPathfinder<T> : CoveragePathfinder<T>
     {
-        public Dictionary<T, T> VisitedNodes { get; } = new Dictionary<T, T>();
-
-        public List<T> ResultPath { get; set; } = new List<T>();
-
-        private readonly HashSet<T> tmpGoals = new HashSet<T>();
-
-        private T searchStart;
-
         private readonly IUnweightedGraph<T> graph;
 
-        private readonly Queue<T> frontier = new Queue<T>();
-
-        private readonly List<T> neighbours = new List<T>();
-
         public BreadthFirstPathfinder(IUnweightedGraph<T> graph)
         {
             this.graph = graph;
         }
 
-        public void Search(T start, T goal)
-        {
-            this.PrepareSearch();
-            this.StartNewSearch(start);
-
-            tmpGoals.Add(goal);
-
-            ContinueSearch();
-        }
-
-        public void Search(T start, HashSet<T> goals)
-        {
-            this.PrepareSearch();
-            this.StartNewSearch(start);
-
-            foreach (var goal in goals)
-            {
-                this.tmpGoals.Add(goal);
-            }
-
-            ContinueSearch();
-        }
-
-        public void Search(T start, int additionalDepth)
-        {
-            this.PrepareSearch();
-            this.StartNewSearch(start);
-
-            InternalSearch(additionalDepth);
-        }
-
-        public void Search(T start, T goal, int additionalDepth)
-        {
-            this.PrepareSearch();
-            this.StartNewSearch(start);
-
-            this.tmpGoals.Add(goal);
-
-            ContinueSearch(additionalDepth);
-        }
-
-        public void Search(T start, HashSet<T> goals, int additionalDepth)
-        {
-            this.PrepareSearch();
-            this.StartNewSearch(start);
-
-            foreach (var goal in goals)
-            {
-                this.tmpGoals.Add(goal);
-            }
-
-            ContinueSearch(additionalDepth);
-        }
-
-        public void ContinueSearch()
-        {
-            this.ResultPath.Clear();
-            if (tmpGoals.Count == 0)
-            {
-                return;
-            }
-
-            ContinueSearch(int.MaxValue);
-        }
-
-        public void ContinueSearch(int additionalDepth)
-        {
-            this.ResultPath.Clear();
-            var (target, isFound) = InternalSearch(additionalDepth);
-            if (isFound)
-            {
-                PathConstructor.RecontructPath(VisitedNodes, searchStart, target, this.ResultPath);
-            }
-        }
-
-        private ValueTuple<T, bool> InternalSearch(int additionalDepth)
+        internal override ValueTuple<T, bool> InternalSearch(int additionalDepth)
         {
             while (frontier.Count > 0 && additionalDepth > 0)
             {
                 additionalDepth--;
                 var current = frontier.Peek();
 
-                if (tmpGoals.Contains(current))
+                if (tmpGoals.Contains(current.Item2))
                 {
-                    tmpGoals.Remove(current);
-                    return (current, true);
+                    tmpGoals.Remove(current.Item2);
+                    return (current.Item2, true);
                 }
 
                 frontier.Dequeue();
-                
-                graph.GetNeighbors(current, neighbours);
-                
+
+                graph.GetNeighbors(current.Item2, neighbours);
+
                 foreach (var next in neighbours)
                 {
-                    if (!VisitedNodes.ContainsKey(next))
+                    var newCost = costSoFar[current.Item2] + 1;
+                    if (!costSoFar.ContainsKey(next) || newCost < costSoFar[next])
                     {
-                        frontier.Enqueue(next);
-                        VisitedNodes.Add(next, current);
+                        costSoFar[next] = newCost;
+                        var priority = newCost;
+                        frontier.Enqueue(new ValueTuple<int, T>(priority, next), priority);
+                        VisitedNodes[next] = current.Item2;
                     }
                 }
             }
 
             return (default(T), false);
         }
-
-        private void PrepareSearch()
-        {
-            this.frontier.Clear();
-            this.VisitedNodes.Clear();
-            this.tmpGoals.Clear();
-        }
-
-        private void StartNewSearch(T start)
-        {
-            this.searchStart = start;
-            this.frontier.Enqueue(start);
-            this.VisitedNodes.Add(start, start);
-        }
     }
 }
diff --git a/BrainAI/Pathfinding/CoveragePathfinder.cs b/BrainAI/Pathfinding/CoveragePathfinder.cs
@@ -0,0 +1,13 @@
+namespace BrainAI.Pathfinding
+{
+    public abstract class CoveragePathfinder<T> : Pathfinder<T>, ICoveragePathfinder<T>
+    {
+        public void Search(T start, int additionalDepth)
+        {
+            this.PrepareSearch();
+            this.StartNewSearch(start);
+
+            InternalSearch(additionalDepth);
+        }
+    }
+}