work on BFS solution

swarm-game · Dec 12, 2023 · 8a9a4df · 8a9a4df
1 parent d564716
commit 8a9a4df
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Showing 2 changed files with 16 additions and 7 deletions.
diff --git a/data/scenarios/Challenges/Mazes/_shortest_path/shortest_path_sol.sw b/data/scenarios/Challenges/Mazes/_shortest_path/shortest_path_sol.sw
@@ -6,13 +6,21 @@ def ifM = \p.\t.\e. b <- p; if b t e end;
 def DFSn : int -> cmd bool = \n.
   // say $ "DFSn at level " ++ format n;
   ifM (ishere "goal") {swap "path"; selfdestruct} {};
-  if (n == 0) {} {
-    ifM (ishere "path") {} {
-      place "path";
-      tL; b <- blocked; bL <- if b {return true} {move; DFSn (n-1)};
-      tR; b <- blocked; bF <- if b {return true} {move; DFSn (n-1)};
-      tR; b <- blocked; bR <- if b {return true} {move; DFSn (n-1)};
-      tL; if (bL && bF && bR) {swap "rock"} {grab}; return ()
+  ifM (ishere "rock") {} {
+    if (n == 0) {} {
+      ifM (ishere "path") {} {
+        place "path";
+        // Weird stuff with let bindings is a workaround for
+        // https://github.com/swarm-game/swarm/issues/681
+        // (see https://github.com/swarm-game/swarm/issues/1032#issuecomment-1402465755)
+        tL; b <- blocked; dead <- if b {return true} {move; DFSn (n-1)};
+        let deadL = dead in
+        tR; b <- blocked; dead <- if b {return true} {move; DFSn (n-1)};
+        let deadF = dead in
+        tR; b <- blocked; dead <- if b {return true} {move; DFSn (n-1)};
+        let deadR = dead in
+        tL; if (deadL && deadF && deadR) {swap "rock"} {grab}; return ()
+      }
     }
   };
   rockhere <- ishere "rock";

diff --git a/data/scenarios/Challenges/Mazes/shortest_path.yaml b/data/scenarios/Challenges/Mazes/shortest_path.yaml
@@ -88,6 +88,7 @@ robots:
       - [50, string]
       - [50, fast grabber]
       - [50, detonator]
+      - [50, dictionary]
       - [1000, rock]
       - [1000, lodestone]
       - [1000, flower]