From 49c713286352c6330ee951c78ec398ae27d51f04 Mon Sep 17 00:00:00 2001
From: Brendan Chen <me@bchen.dev>
Date: Wed, 25 Feb 2026 16:46:21 -0800
Subject: [PATCH] Add queues and homework

---
 .../notes-and-examples/2026.02.28/homework.py |  2 +
 .../notes-and-examples/2026.02.28/queues.py   | 51 +++++++++++++++++++
 2 files changed, 53 insertions(+)
 create mode 100644 shared/notes-and-examples/2026.02.28/homework.py
 create mode 100644 shared/notes-and-examples/2026.02.28/queues.py

diff --git a/shared/notes-and-examples/2026.02.28/homework.py b/shared/notes-and-examples/2026.02.28/homework.py
new file mode 100644
index 0000000..5c6267f
--- /dev/null
+++ b/shared/notes-and-examples/2026.02.28/homework.py
@@ -0,0 +1,2 @@
+# Homework:
+# See youtube-playlists under Assignments
diff --git a/shared/notes-and-examples/2026.02.28/queues.py b/shared/notes-and-examples/2026.02.28/queues.py
new file mode 100644
index 0000000..0004175
--- /dev/null
+++ b/shared/notes-and-examples/2026.02.28/queues.py
@@ -0,0 +1,51 @@
+class Node:
+    next_node: "None | Node" = None
+    prev_node: "None | Node" = None
+
+    def __init__(self, value):
+        self.value = value
+
+class Queue:
+    front: "Node | None" = None
+    back: "Node | None" = None
+
+    def append(self, value):
+        if self.back is None:
+            self.front = Node(value)
+            self.back = self.front
+        else:
+            new_node = Node(value)
+            self.back.prev_node = new_node
+            new_node.next_node = self.back
+            self.back = new_node
+    
+    def popleft(self):
+        if self.front is not None:
+            prev_front = self.front
+
+            prev_node_in_queue = self.front.prev_node
+            self.front.next_node = None
+            self.front.prev_node = None
+            if prev_node_in_queue is not None:
+                prev_node_in_queue.next_node = None
+
+            self.front = prev_node_in_queue
+            
+            return prev_front
+        else:
+            return None
+
+    def print_queue(self):
+        current_node = self.front
+        while current_node is not None:
+            print(current_node.value)
+            current_node = current_node.prev_node
+
+
+queue = Queue()
+queue.append("first")
+queue.append("second")
+queue.append("third")
+queue.popleft()
+queue.popleft()
+queue.print_queue()