From 30ed87d9e949a24ddd481f8912e206def3ab2572 Mon Sep 17 00:00:00 2001
From: Brian Chu <brianmchu42@gmail.com>
Date: Fri, 7 Jan 2022 11:02:27 -0800
Subject: use nuget for A* search instead of copypasta

---
 day13.fsx | 48 ++----------------------------------------------
 1 file changed, 2 insertions(+), 46 deletions(-)

diff --git a/day13.fsx b/day13.fsx
index a20a14a..d84e707 100644
--- a/day13.fsx
+++ b/day13.fsx
@@ -1,49 +1,5 @@
-type Config<'a> = 
-    {
-        neighbours: 'a -> seq<'a>
-        gCost: 'a -> 'a -> float
-        fCost: 'a -> 'a -> float
-        maxIterations: int option
-    }
-
-let search<'a when 'a : comparison> start goal config : seq<'a> option =
-
-    let rec reconstructPath cameFrom current =
-        seq {
-            yield current
-            match Map.tryFind current cameFrom with
-            | None -> ()
-            | Some next -> yield! reconstructPath cameFrom next
-        }
-
-    let rec crawler closedSet (openSet, gScores, fScores, cameFrom) =
-        match config.maxIterations with 
-        | Some n when n = Set.count closedSet -> None
-        | _ ->
-            match List.sortBy (fun n -> Map.find n fScores) openSet with
-            | current::_ when current = goal -> Some <| reconstructPath cameFrom current 
-            | current::rest ->
-                let gScore = Map.find current gScores
-                let next =
-                    config.neighbours current 
-                    |> Seq.filter (fun n -> closedSet |> Set.contains n |> not)
-                    |> Seq.fold (fun (openSet, gScores, fScores, cameFrom) neighbour ->
-                        let tentativeGScore = gScore + config.gCost current neighbour
-                        if List.contains neighbour openSet && tentativeGScore >= Map.find neighbour gScores 
-                        then (openSet, gScores, fScores, cameFrom)
-                        else
-                            let newOpenSet = if List.contains neighbour openSet then openSet else neighbour::openSet
-                            let newGScores = Map.add neighbour tentativeGScore gScores
-                            let newFScores = Map.add neighbour (tentativeGScore + config.fCost neighbour goal) fScores
-                            let newCameFrom = Map.add neighbour current cameFrom
-                            newOpenSet, newGScores, newFScores, newCameFrom
-                        ) (rest, gScores, fScores, cameFrom)
-                crawler (Set.add current closedSet) next
-            | _ -> None
-
-    let gScores = Map.ofList [start, 0.]
-    let fScores = Map.ofList [start, config.fCost start goal]
-    crawler Set.empty ([start], gScores, fScores, Map.empty)
+#r "nuget: astar-search, 1.0.2"
+open AStar
 
 let isWall (x, y) =
     let bits = System.Convert.ToString(x*x + 3*x + 2*x*y + y + y*y + 1350, 2)
-- 
cgit 1.4.1-2-gfad0