From d27cefdf23590764ea1d015b677b655adbf32065 Mon Sep 17 00:00:00 2001
From: Alex-m2 <alex.ong@unsw.edu.au>
Date: Sat, 23 Dec 2023 21:22:21 +1100
Subject: [PATCH] day23: stub for Path

---
 day23/lib/classes.py        | 30 ++++++++++++++++++++++++++++++
 day23/tests/test_classes.py | 16 +++++++++++++++-
 2 files changed, 45 insertions(+), 1 deletion(-)

diff --git a/day23/lib/classes.py b/day23/lib/classes.py
index 123279b..239c753 100644
--- a/day23/lib/classes.py
+++ b/day23/lib/classes.py
@@ -16,6 +16,36 @@ def copy_modify(
             col = self.col
         return Position(row, col)
 
+    def __str__(self) -> str:
+        return f"{self.row}, {self.col}"
+
+
+class Path:
+    route: list[Position]
+    nodes: set[Position]
+
+    def __init__(self) -> None:
+        self.route = []
+        self.nodes = set()
+
+    def can_add(self, position: Position) -> bool:
+        return position not in self.nodes
+
+    def add(self, position: Position) -> None:
+        self.route.append(position)
+        self.nodes.add(position)
+
+    def copy(self) -> "Path":
+        result = Path()
+        result.route = self.route[:]
+        result.nodes = set(result.route)
+        return result
+
+    def last(self) -> Position:
+        if len(self.route) == 0:
+            raise ValueError("Don't call last when i'm empty 4head")
+        return self.route[-1]
+
 
 class Maze:
     grid: list[str]  # 2d array of chars
diff --git a/day23/tests/test_classes.py b/day23/tests/test_classes.py
index 7064ab3..6823840 100644
--- a/day23/tests/test_classes.py
+++ b/day23/tests/test_classes.py
@@ -1,5 +1,5 @@
 from day23.day23 import INPUT_SMALL
-from day23.lib.classes import Maze, Position
+from day23.lib.classes import Maze, Path, Position
 from day23.lib.parsers import get_maze
 
 
@@ -18,3 +18,17 @@ def test_maze() -> None:
     assert maze[Position(0, 0)] == "#"
     assert maze[Position(0, 1)] == "."
     assert maze[Position(-1, 0)] is None
+
+
+def test_path() -> None:
+    path = Path()
+    path.add(Position(0, 0))
+    path.add(Position(0, 1))
+    assert path.last() == Position(0, 1)
+
+    path2 = path.copy()
+
+    assert path2.last() == Position(0, 1)
+    path2.add(Position(0, 2))
+    assert path.last() == Position(0, 1)
+    assert path2.last() == Position(0, 2)