From 54f5801f41d504f1b340491ee928cf32582d563e Mon Sep 17 00:00:00 2001
From: pathywang <pathywang@gmail.com>
Date: Sun, 4 Oct 2026 05:20:49 +0100
Subject: [PATCH 1/3] complete linked-list

---
 Sprint-2/implement_linked_list/linked_list.py | 55 +++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/Sprint-2/implement_linked_list/linked_list.py b/Sprint-2/implement_linked_list/linked_list.py
index e69de29b..bb562246 100644
--- a/Sprint-2/implement_linked_list/linked_list.py
+++ b/Sprint-2/implement_linked_list/linked_list.py
@@ -0,0 +1,55 @@
+class Node:
+    def __init__(self, value):
+        self.value = value
+        self.next = None
+        self.previous = None
+
+class LinkedList:
+    def __init__(self):
+        self.head = None
+        self.tail = None
+
+    def push_head(self, value):
+        node = Node(value)
+
+        if self.head is None:
+            self.head = node
+            self.tail = node
+        else:
+            node.next = self.head
+            self.head.previous = node
+            self.head = node
+
+        return node
+
+    def pop_tail(self):
+        node = self.tail
+
+        if node is None:
+            return None
+
+        if self.head == self.tail:
+            self.head = None
+            self.tail = None
+        else:
+            self.tail = node.previous
+            self.tail.next = None
+
+        return node.value
+
+    def remove(self, node):
+        if node == self.head and node == self.tail:
+            self.head = None
+            self.tail = None
+
+        elif node == self.head:
+            self.head = node.next
+            self.head.previous = None
+
+        elif node == self.tail:
+            self.tail = node.previous
+            self.tail.next = None
+
+        else:
+            node.previous.next = node.next
+            node.next.previous = node.previous
\ No newline at end of file

From 6aabe2c7c4a9dc38399be5ad16d1e7260e20d62f Mon Sep 17 00:00:00 2001
From: pathywang <pathywang@gmail.com>
Date: Fri, 9 Oct 2026 21:43:53 +0100
Subject: [PATCH 2/3] correction

---
 Sprint-2/implement_linked_list/linked_list.py | 14 +++++++-------
 1 file changed, 7 insertions(+), 7 deletions(-)

diff --git a/Sprint-2/implement_linked_list/linked_list.py b/Sprint-2/implement_linked_list/linked_list.py
index bb562246..61aae11e 100644
--- a/Sprint-2/implement_linked_list/linked_list.py
+++ b/Sprint-2/implement_linked_list/linked_list.py
@@ -1,4 +1,6 @@
 class Node:
+     __slots__ = ("value", "next", "previous")
+
     def __init__(self, value):
         self.value = value
         self.next = None
@@ -28,12 +30,7 @@ def pop_tail(self):
         if node is None:
             return None
 
-        if self.head == self.tail:
-            self.head = None
-            self.tail = None
-        else:
-            self.tail = node.previous
-            self.tail.next = None
+        self.remove(node)
 
         return node.value
 
@@ -52,4 +49,7 @@ def remove(self, node):
 
         else:
             node.previous.next = node.next
-            node.next.previous = node.previous
\ No newline at end of file
+            node.next.previous = node.previous
+
+        node.next = None
+        node.previous = None
\ No newline at end of file

From 64a9e425b70a0ecbe98b5f8ff797812ef859e3fd Mon Sep 17 00:00:00 2001
From: pathywang <pathywang@gmail.com>
Date: Fri, 9 Oct 2026 22:27:47 +0100
Subject: [PATCH 3/3] correction

---
 Sprint-2/implement_linked_list/linked_list.py | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Sprint-2/implement_linked_list/linked_list.py b/Sprint-2/implement_linked_list/linked_list.py
index 61aae11e..5999a955 100644
--- a/Sprint-2/implement_linked_list/linked_list.py
+++ b/Sprint-2/implement_linked_list/linked_list.py
@@ -1,5 +1,5 @@
 class Node:
-     __slots__ = ("value", "next", "previous")
+    __slots__ = ("value", "next", "previous")
 
     def __init__(self, value):
         self.value = value