daily commit 2024-05-11

2024-05-11/README.md

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+# Codecademy doubly linked list implementation
+This is doubly linked list created in codecademy "Learn Data Structures and Algorithms with Python" course.
+
+Link to course: https://www.codecademy.com/enrolled/courses/learn-data-structures-and-algorithms-with-python

2024-05-11/main.py

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+class Node:
+  def __init__(self, value, next_node=None, prev_node=None):
+    self.value = value
+    self.next_node = next_node
+    self.prev_node = prev_node
+
+  def set_next_node(self, next_node):
+    self.next_node = next_node
+
+  def get_next_node(self):
+    return self.next_node
+
+  def set_prev_node(self, prev_node):
+    self.prev_node = prev_node
+
+  def get_prev_node(self):
+    return self.prev_node
+
+  def get_value(self):
+    return self.value
+
+
+class DoublyLinkedList:
+  def __init__(self):
+    self.head_node = None
+    self.tail_node = None
+
+  def add_to_head(self, new_value):
+    new_head = Node(new_value)
+    current_head = self.head_node
+
+    if current_head != None:
+      current_head.set_prev_node(new_head)
+      new_head.set_next_node(current_head)
+
+    self.head_node = new_head
+
+    if self.tail_node == None:
+      self.tail_node = new_head
+
+  def add_to_tail(self, new_value):
+    new_tail = Node(new_value)
+    current_tail = self.tail_node
+
+    if current_tail != None:
+      current_tail.set_next_node(new_tail)
+      new_tail.set_prev_node(current_tail)
+
+    self.tail_node = new_tail
+
+    if self.head_node == None:
+      self.head_node = new_tail
+
+  def remove_head(self):
+    removed_head = self.head_node
+
+    if removed_head == None:
+      return None
+
+    self.head_node = removed_head.get_next_node()
+
+    if self.head_node != None:
+      self.head_node.set_prev_node(None)
+
+    if removed_head == self.tail_node:
+      self.remove_tail()
+
+    return removed_head.get_value()
+
+  def remove_tail(self):
+    removed_tail = self.tail_node
+
+    if removed_tail == None:
+      return None
+
+    self.tail_node = removed_tail.get_prev_node()
+
+    if self.tail_node != None:
+      self.tail_node.set_next_node(None)
+
+    if removed_tail == self.head_node:
+      self.remove_head()
+
+    return removed_tail.get_value()
+
+  def remove_by_value(self, value_to_remove):
+    node_to_remove = None
+    current_node = self.head_node
+
+    while current_node != None:
+      if current_node.get_value() == value_to_remove:
+        node_to_remove = current_node
+        break
+
+      current_node = current_node.get_next_node()
+
+    if node_to_remove == None:
+      return None
+
+    if node_to_remove == self.head_node:
+      self.remove_head()
+    elif node_to_remove == self.tail_node:
+      self.remove_tail()
+    else:
+      next_node = node_to_remove.get_next_node()
+      prev_node = node_to_remove.get_prev_node()
+      next_node.set_prev_node(prev_node)
+      prev_node.set_next_node(next_node)
+
+    return node_to_remove
+
+  def stringify_list(self):
+    string_list = ""
+    current_node = self.head_node
+    while current_node:
+      if current_node.get_value() != None:
+        string_list += str(current_node.get_value()) + "\n"
+      current_node = current_node.get_next_node()
+    return string_list