From 8690ab12904c2673db74ec9fdfc52f5b8d8bf2dc Mon Sep 17 00:00:00 2001
From: Tomasz Kramkowski <tomasz@kramkow.ski>
Date: Fri, 16 Dec 2022 16:02:07 +0000
Subject: 16 much shorter

---
 16.py | 22 +++++++---------------
 1 file changed, 7 insertions(+), 15 deletions(-)

diff --git a/16.py b/16.py
index acddc1f..779b8aa 100644
--- a/16.py
+++ b/16.py
@@ -41,22 +41,14 @@ def sum_flow(open_valves):
 def recurse(open_valves=frozenset(), current='AA', flow=0, time_left=30):
     cflow = sum_flow(open_valves)
     cnode = nodes[current]
-    best = 0
-    def loop():
-        nonlocal best
-        best = max(best, flow + cflow * time_left)
-        for neighbour, cost in cnode.neighbours:
-            if cost >= time_left: continue
-            new = recurse(open_valves, neighbour,
-                          flow + cflow * cost, time_left - cost)
-            best = max(best, new)
-    loop()
+    best = flow + cflow * time_left
+    for neighbour, cost in cnode.neighbours:
+        if cost >= time_left: continue
+        new = recurse(open_valves, neighbour,
+                      flow + cflow * cost, time_left - cost)
+        best = max(best, new)
     if current not in open_valves and time_left > 0 and cnode.flow > 0:
-        flow += cflow
-        open_valves |= {current}
-        cflow = sum_flow(open_valves)
-        time_left -= 1
-        loop()
+        best = max(best, recurse(open_valves | {current}, current, flow + cflow, time_left - 1))
     return best
 
 print(recurse())
-- 
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