From a70226032b43af697bdab9418c487d3400155a9c Mon Sep 17 00:00:00 2001
From: Pascal Lais <pascal@lais.dev>
Date: Mon, 13 Dec 2021 08:54:11 +0100
Subject: [PATCH] Update day 12 solution

Use deque instead of list
---
 day-12/day-12.py | 17 +++++++++++------
 1 file changed, 11 insertions(+), 6 deletions(-)

diff --git a/day-12/day-12.py b/day-12/day-12.py
index 603edbc..8e07024 100644
--- a/day-12/day-12.py
+++ b/day-12/day-12.py
@@ -1,11 +1,12 @@
 #!/usr/bin/env python3
 from pathlib import Path
+from collections import deque
 
 
 def process_node(node, available_edges, visited):
-    paths = []
+    paths = deque()
     if node == "end":
-        paths.append([node])
+        paths.append(deque(node))
         return paths
     if node.islower():
         visited.add(node)
@@ -13,16 +14,18 @@ def process_node(node, available_edges, visited):
     for n in neighbors:
         if n not in visited:
             nxt = process_node(n, available_edges, visited)
-            paths += [[node] + p for p in nxt]
+            for p in nxt:
+                p.appendleft(node)
+                paths.append(p)
     if node in visited:
         visited.remove(node)
     return paths
 
 
 def process_node_twice(node, available_edges, visited, visited_twice):
-    paths = []
+    paths = deque()
     if node == "end":
-        paths.append([node])
+        paths.append(deque(node))
         return paths
     if node.islower():
         if node in visited and visited_twice:
@@ -35,7 +38,9 @@ def process_node_twice(node, available_edges, visited, visited_twice):
     for n in neighbors:
         if n not in visited or visited_twice != node and n != "start":
             nxt = process_node_twice(n, available_edges, visited, visited_twice)
-            paths += [[node] + p for p in nxt]
+            for p in nxt:
+                p.appendleft(node)
+                paths.append(p)
     if visited_twice == node:
         visited_twice = None
     elif node in visited: