From 79fc85b28d1269cf62b311c8c3eecc9c5798af94 Mon Sep 17 00:00:00 2001
From: marina <138340846+bt3gl-cryptographer@users.noreply.github.com>
Date: Wed, 2 Aug 2023 18:34:17 -0700
Subject: [PATCH] Create doubly_linked_list_II.py

---
 linked_lists/doubly_linked_list_II.py | 74 +++++++++++++++++++++++++++
 1 file changed, 74 insertions(+)
 create mode 100644 linked_lists/doubly_linked_list_II.py

diff --git a/linked_lists/doubly_linked_list_II.py b/linked_lists/doubly_linked_list_II.py
new file mode 100644
index 0000000..b5e6142
--- /dev/null
+++ b/linked_lists/doubly_linked_list_II.py
@@ -0,0 +1,74 @@
+#!/usr/bin/env python3
+# -*- coding: utf-8 -*-
+# author: bt3gl
+
+
+class Node:
+    
+    def __init__(self, val):
+        self.val = val
+        self.next = None
+        self.prev = None
+
+class MyLinkedList:
+
+    def __init__(self):
+        self.head = Node(0)
+        self.len = 0
+        
+    def _loop(self , index):
+        node = self.head
+        p = 0
+        while p < index + 1:
+            node = node.next
+            p += 1
+        
+        return node
+        
+    def get(self, index: int) -> int:
+        if self.len <= index or index < 0:
+            return -1
+        node = self._loop(index)
+        return node.val
+
+    def addAtHead(self, val: int) -> None:
+        self.addAtIndex(0, val)
+
+    def addAtTail(self, val: int) -> None:
+        self.addAtIndex(self.len, val)
+        
+    def addAtIndex(self, index: int, val: int) -> None:
+        if self.len < index:
+            return -1
+
+        if index < 0:
+            index = 0
+        
+        self.len += 1
+
+        node = self.head
+        for _ in range(index):
+            node = node.next
+    
+        new_node = Node(val)
+        new_node.next = node.next
+        new_node.prev = node
+        node.next = new_node
+
+    def deleteAtIndex(self, index: int) -> None:
+        
+        if self.len <= index or index < 0:
+            return -1
+        
+        self.len -= 1
+
+        node = self.head
+        for _ in range(index):
+            node = node.next
+        
+        node.next.prev = node
+        node.next = node.next.next
+        
+        
+        
+