Similarly fix day 20

1 files changed, 3 insertions, 1 deletions

diff --git a/2019/20.hs b/2019/20.hs
index 8deb4e8..1f51c46 100644
--- a/2019/20.hs
+++ b/2019/20.hs
@@ -23,7 +23,9 @@ shortestPath nextf heuristic startnode target = go 0 (Set.singleton (heuristic s
             visited' = Map.insert node dist visited
         in if node == target
                then dist
-               else go (ctr + 1) pqueue' visited'
+               else if maybe True (dist <) (Map.lookup node visited)
+                   then go (ctr + 1) pqueue' visited'
+                   else go (ctr + 1) newpqueue visited
 
 main :: IO ()
 main = do