Update day 12 solution

day-12/day-12.py

@@ -1,25 +1,20 @@
 #!/usr/bin/env python3
 from pathlib import Path
-from collections import deque
 
 
 def process_node(node, available_edges, visited):
-    paths = deque()
+    num_paths = 0
     if node == "end":
-        paths.append(deque(node))
-        return paths
+        return 1
     if node.islower():
         visited.add(node)
     neighbors = [n for e in available_edges if node in e for n in e if n != node]
     for n in neighbors:
         if n not in visited:
-            nxt = process_node(n, available_edges, visited)
-            for p in nxt:
-                p.appendleft(node)
-            paths += nxt
+            num_paths += process_node(n, available_edges, visited)
     if node in visited:
         visited.remove(node)
-    return paths
+    return num_paths
 
 
 def process_node_twice(node, available_edges, visited, visited_twice):