Add day 8

advent-of-code/Program.fs

@@ -32,4 +32,8 @@ let main _ =
     printfn $"%A{day7Star1}"
     let day7Star2 = day_7.Star2.main
     printfn $"%A{day7Star2}"
+    let day8Star1 = day_8.Star1.main
+    printfn $"%A{day8Star1}"
+    let day8Star2 = day_8.Star2.main
+    printfn $"%A{day8Star2}"
     0

advent-of-code/tasks/day-8/Star1.fs

@@ -0,0 +1,81 @@
+module advent_of_code.tasks.day_8.Star1
+
+open System
+open System.IO
+
+let stream = new StreamReader("tasks/day-8/input.txt")
+
+type Point3D =
+    struct
+        val X: float
+        val Y: float
+        val Z: float
+        new(s: string) =
+            let splitS = s.Split(',') |> Array.map float
+            let x, y, z = splitS[0], splitS[1], splitS[2]
+            { X = x; Y = y; Z = z }
+
+        member this.GetDistanceFrom(p: Point3D) =
+            ((p.X - this.X) ** 2 + (p.Y - this.Y) ** 2 + (p.Z - this.Z) ** 2) |> sqrt
+
+        override this.ToString() =
+            $"Point3D X = {this.X} Y = {this.Y} Z = {this.Z}"
+    end
+
+type DisjointSet =
+    struct
+        val Parent: Map<Point3D, Point3D>
+        val Size: Map<Point3D, int>
+        new(parent: Map<Point3D, Point3D>, size: Map<Point3D, int>) =
+            {
+                Parent = parent
+                Size = size
+            }
+        new(points: Point3D array) =
+            {
+                Parent = points |> Array.fold (fun (map: Map<Point3D, Point3D>) (point: Point3D) -> map.Add(point, point)) Map.empty
+                Size = points |> Array.fold (fun (map: Map<Point3D, int>) (point: Point3D) -> map.Add(point, 1)) Map.empty
+            }
+        
+        member this.Find (point: Point3D) =
+            let p2 = this.Parent[point]
+            if (p2 = point) then
+                this, point
+            else
+                let disjoint, p = this.Find p2
+                let parent = disjoint.Parent.Add(point, p)
+                DisjointSet(parent, this.Size), p
+        
+        member this.Union (connection: Point3D * Point3D) =
+            let p1, p2 = connection.Deconstruct()
+            let disjointSet, p1 = this.Find(p1)
+            let disjointSet, p2 = disjointSet.Find(p2)
+            if p1 = p2 then
+                disjointSet
+            else
+                let parent = disjointSet.Parent.Add(p2, p1)
+                let size = disjointSet.Size.Add(p1, disjointSet.Size[p1] + disjointSet.Size[p2]).Add(p2, 0)
+                DisjointSet(parent, size)
+    end
+
+let connectionFilter (ci: (Point3D * Point3D) * int) =
+    let c, i = ci.Deconstruct()
+    let p1, p2 = c.Deconstruct()
+    i % 2 = 0 && p1.GetDistanceFrom p2 <> 0
+
+let removeIndex (ci: (Point3D * Point3D) * int) =
+    let c, _ = ci.Deconstruct()
+    c
+
+let sortKey (c: Point3D * Point3D) =
+    let p1, p2 = c.Deconstruct()
+    p1.GetDistanceFrom p2
+
+let main =
+    let points = stream.ReadToEnd().Split('\n') |> Array.map Point3D
+    let connections = ((Array.allPairs points points) |> Array.sortBy sortKey |> Array.mapi (fun i el -> el, i) |> Array.filter connectionFilter |> Array.map removeIndex)[.. 999]
+    let disjointSet = DisjointSet(points)
+    let completeDS = connections |> Array.fold (fun (ds: DisjointSet) (connection: Point3D * Point3D) -> ds.Union(connection)) disjointSet
+    let sizes = completeDS.Size.Values |> Seq.sort |> Array.ofSeq
+    Array.Reverse sizes
+    sizes[..2] |> Array.fold (*) 1

advent-of-code/tasks/day-8/Star2.fs

@@ -0,0 +1,88 @@
+module advent_of_code.tasks.day_8.Star2
+
+open System
+open System.IO
+
+let stream = new StreamReader("tasks/day-8/input.txt")
+
+type Point3D =
+    struct
+        val X: float
+        val Y: float
+        val Z: float
+        new(s: string) =
+            let splitS = s.Split(',') |> Array.map float
+            let x, y, z = splitS[0], splitS[1], splitS[2]
+            { X = x; Y = y; Z = z }
+
+        member this.GetDistanceFrom(p: Point3D) =
+            ((p.X - this.X) ** 2 + (p.Y - this.Y) ** 2 + (p.Z - this.Z) ** 2) |> sqrt
+
+        override this.ToString() =
+            $"Point3D X = {this.X} Y = {this.Y} Z = {this.Z}"
+    end
+
+type DisjointSet =
+    struct
+        val Parent: Map<Point3D, Point3D>
+        val Size: Map<Point3D, int>
+        new(parent: Map<Point3D, Point3D>, size: Map<Point3D, int>) =
+            {
+                Parent = parent
+                Size = size
+            }
+        new(points: Point3D array) =
+            {
+                Parent = points |> Array.fold (fun (map: Map<Point3D, Point3D>) (point: Point3D) -> map.Add(point, point)) Map.empty
+                Size = points |> Array.fold (fun (map: Map<Point3D, int>) (point: Point3D) -> map.Add(point, 1)) Map.empty
+            }
+        
+        member this.Find (point: Point3D) =
+            let p2 = this.Parent[point]
+            if (p2 = point) then
+                this, point
+            else
+                let disjoint, p = this.Find p2
+                let parent = disjoint.Parent.Add(point, p)
+                DisjointSet(parent, this.Size), p
+        
+        member this.Union (connection: Point3D * Point3D) =
+            let p1, p2 = connection.Deconstruct()
+            let disjointSet, p1 = this.Find(p1)
+            let disjointSet, p2 = disjointSet.Find(p2)
+            if p1 = p2 then
+                disjointSet
+            else
+                let parent = disjointSet.Parent.Add(p2, p1)
+                let size = disjointSet.Size.Add(p1, disjointSet.Size[p1] + disjointSet.Size[p2]).Add(p2, 0)
+                DisjointSet(parent, size)
+    end
+
+let connectionFilter (ci: (Point3D * Point3D) * int) =
+    let c, i = ci.Deconstruct()
+    let p1, p2 = c.Deconstruct()
+    i % 2 = 0 && p1.GetDistanceFrom p2 <> 0
+
+let removeIndex (ci: (Point3D * Point3D) * int) =
+    let c, _ = ci.Deconstruct()
+    c
+
+let sortKey (c: Point3D * Point3D) =
+    let p1, p2 = c.Deconstruct()
+    p1.GetDistanceFrom p2
+
+let addIfNecessary (dsn: DisjointSet * float) (connection: Point3D * Point3D) =
+    let ds, n = dsn.Deconstruct()
+    let p1, p2 = connection.Deconstruct()
+    if (n <> 0) then
+        ds, n
+    else
+        let newDisjointSet = ds.Union(connection)
+        newDisjointSet, if newDisjointSet.Size.Values |> Seq.max = 1000 then p1.X * p2.X else n
+
+let main =
+    let points = stream.ReadToEnd().Split('\n') |> Array.map Point3D
+    let connections = ((Array.allPairs points points) |> Array.sortBy sortKey |> Array.mapi (fun i el -> el, i) |> Array.filter connectionFilter |> Array.map removeIndex)
+    let disjointSet = DisjointSet(points)
+    let _, n = connections |> Array.fold addIfNecessary (disjointSet, 0)
+    n |> int