Add FindShortestRoute Travelling salesman problem

OpenMEPSandbox/Algo/TravellingSaleman.cs

@@ -0,0 +1,109 @@
+using Autodesk.DesignScript.Geometry;
+using Autodesk.DesignScript.Runtime;
+
+namespace OpenMEPSandbox.Algo;
+
+[IsVisibleInDynamoLibrary(false)]
+public static class TravellingSalesman
+{
+
+    /// <summary>
+    /// takes a list of 3D points as input and returns the shortest route that visits each point exactly once
+    /// </summary>
+    /// <param name="points"></param>
+    /// <returns></returns>
+    public static List<Point> FindShortestRoute(List<Point> points)
+    {
+        List<Point> shortestRoute = null;
+        double shortestDistance = double.MaxValue;
+
+        // Generate all possible permutations of the points
+        List<List<Point>> permutations = Permute(points);
+
+        // For each permutation, calculate the total distance and keep track of the shortest route
+        foreach (List<Point> route in permutations)
+        {
+            double totalDistance = CalculateTotalDistance(route);
+            if (totalDistance < shortestDistance)
+            {
+                shortestDistance = totalDistance;
+                shortestRoute = route;
+            }
+        }
+
+        return shortestRoute;
+    }
+
+    /// <summary>
+    /// takes a list of 3D points as input and returns a list of all possible permutations of the input list
+    /// </summary>
+    /// <param name="points"></param>
+    /// <returns></returns>
+    static List<List<Point>> Permute(List<Point> points)
+    {
+        List<List<Point>> result = new List<List<Point>>();
+        PermuteHelper(points, 0, result);
+        return result;
+    }
+
+    /// <summary>
+    /// takes three arguments: the input list of points, the current index to swap, and the list to store the permutations
+    /// </summary>
+    /// <param name="points"></param>
+    /// <param name="index"></param>
+    /// <param name="result"></param>
+    static void PermuteHelper(List<Point> points, int index, List<List<Point>> result)
+    {
+        if (index >= points.Count)
+        {
+            result.Add(new List<Point>(points));
+        }
+        else
+        {
+            for (int i = index; i < points.Count; i++)
+            {
+                Swap(points, index, i);
+                PermuteHelper(points, index + 1, result);
+                Swap(points, index, i);
+            }
+        }
+    }
+
+    /// <summary>
+    ///  takes a list of points and two indices and swaps the elements at those indices in the list.
+    /// </summary>
+    /// <param name="points"></param>
+    /// <param name="i"></param>
+    /// <param name="j"></param>
+    static void Swap(List<Point> points, int i, int j)
+    {
+        (points[i], points[j]) = (points[j], points[i]);
+    }
+
+    static double CalculateTotalDistance(List<Point> route)
+    {
+        double totalDistance = 0;
+        for (int i = 0; i < route.Count - 1; i++)
+        {
+            totalDistance += CalculateDistance(route[i], route[i + 1]);
+        }
+
+        totalDistance += CalculateDistance(route[route.Count - 1], route[0]);
+        return totalDistance;
+    }
+
+    /// <summary>
+    /// calculates the distance between two points by using euclidean distance formula
+    /// </summary>
+    /// <param name="point1">the first point</param>
+    /// <param name="point2">the second point</param>
+    /// <returns>distance between two point</returns>
+    static double CalculateDistance(Autodesk.DesignScript.Geometry.Point point1,
+        Autodesk.DesignScript.Geometry.Point point2)
+    {
+        double dx = point2.X - point1.X;
+        double dy = point2.Y - point1.Y;
+        double dz = point2.Z - point1.Z;
+        return Math.Sqrt(dx * dx + dy * dy + dz * dz);
+    }
+}

OpenMEPSandbox/Geometry/Point.cs

@@ -432,4 +432,27 @@ public static double CompareTo(Autodesk.DesignScript.Geometry.Point point1,
         int compareTo = point1.ToGSharkType().CompareTo(point2.ToGSharkType());
         return compareTo;
     }
+
+    /// <summary>
+    /// takes a list of 3D points as input and returns the shortest route that visits each point exactly once'
+    /// https://en.wikipedia.org/wiki/Travelling_salesman_problem
+    /// </summary>
+    /// <param name="points">the list 3d points</param>
+    /// <returns name="lines"> shortest route</returns>
+    /// <example>
+    /// ![](../OpenMEPPage/geometry/dyn/pic/Point.FindShortestRoute.gif)
+    /// </example>
+    public static List<Autodesk.DesignScript.Geometry.Line> FindShortestRoute(List<Autodesk.DesignScript.Geometry.Point> points)
+    {
+        List<Autodesk.DesignScript.Geometry.Point> shortestRoute = TravellingSalesman.FindShortestRoute(points);
+        // connect line 
+        List<Autodesk.DesignScript.Geometry.Line> lines = new List<Autodesk.DesignScript.Geometry.Line>();
+        for (int i = 0; i < shortestRoute.Count - 1; i++)
+        {
+            Autodesk.DesignScript.Geometry.Line line =
+                Autodesk.DesignScript.Geometry.Line.ByStartPointEndPoint(shortestRoute[i], shortestRoute[i + 1]);
+            lines.Add(line);
+        }
+        return lines;
+    }
 }