Added linked and doublely-linked list Python code

This commit is contained in:
Donald Calloway 2025-10-07 17:56:39 -07:00
parent 5a96497b69
commit 3ae086fb58

View File

@ -1,15 +1,99 @@
class Node:
def __init__(self, data):
self.data = data
def __init__(self, index, x:int, y:int):
self.index = index
self.data = (x, y)
self.prev = None
self.next = None
class LinkedList:
def __init__(self, x:int, y: int):
self.data = (x, y)
self.head = None
def append(self, x:int, y:int):
new_node = Node(None, x, y)
if not self.head:
self.head = new_node
return
current = self.head
while current.next:
current = current.next
current.next = new_node
def insert(self, index, x: int, y:int):
new_node = Node(index, x, y)
if not self.head or index == 0:
new_node.next = self.head
if self.head:
self.head.prev = new_node
self.head = new_node
return
current = self.head
prev = None
curr_index = 0
while current and curr_index < index:
prev = current
current = current.next
curr_index += 1
new_node.next = current
if current:
current.prev = new_node
prev.next = new_node
new_node.prev = prev
def delete(self, index: int):
if not self.head:
print("List is empty.")
return
current = self.head
curr_index = 0
# Deleting the head node
if index == 0:
self.head = current.next
if self.head:
self.head.prev = None
return
# Traverse to the node at the given index
while current and curr_index < index:
current = current.next
curr_index += 1
if not current:
print("Index out of bounds.")
return
# Re-link the previous and next nodes
if current.prev:
current.prev.next = current.next
if current.next:
current.next.prev = current.prev
def to_list(self):
result = []
current = self.head
while current:
result.append(current.data)
current = current.next
return result
def display_forward(self):
current = self.head
while current:
print(current.data, end=" -> ")
current = current.next
print("None")
class DoublyLinkedList:
def __init__(self):
self.head = None
def append(self, data):
new_node = Node(data)
def append(self, x, y):
new_node = Node(None, x, y)
if not self.head:
self.head = new_node
return
@ -19,8 +103,8 @@ class DoublyLinkedList:
current.next = new_node
new_node.prev = current
def insert(self, index, data):
new_node = Node(data)
def insert(self, index, x, y):
new_node = Node(None, x, y)
if index == 0:
new_node.next = self.head
if self.head:
@ -40,10 +124,10 @@ class DoublyLinkedList:
current.next.prev = new_node
current.next = new_node
def delete(self, data):
def delete(self, x, y):
current = self.head
while current:
if current.data == data:
if current.data == (x, y):
if current.prev:
current.prev.next = current.next
else:
@ -52,7 +136,7 @@ class DoublyLinkedList:
current.next.prev = current.prev
return
current = current.next
raise ValueError(f"{data} not found in list")
raise ValueError(f"{(x, y)} not found in list")
def reverse(self):
current = self.head
@ -102,15 +186,28 @@ class DoublyLinkedList:
current = current.prev
print("None")
ll = LinkedList(0, 0)
ll.append(0, 10)
ll.append(10, 20)
ll.append(20, 30)
ll.append(30, 40)
ll.insert(1, 11, 15)
ll.insert(2, 16, 20)
ll.delete(1)
ll.display_forward()
dll = DoublyLinkedList()
dll.append(10)
dll.append(20)
dll.append(30)
dll.insert(1, 15) # Insert 15 at index 1
dll.delete(20) # Remove node with value 20
dll.append(10, 6)
dll.append(20, 5)
dll.append(30, 3)
dll.insert(1, 15, 10) # Insert 15 at index 1
dll.delete(20, 5) # Remove node with value 20
dll.reverse() # Reverse the list
print("Index of 15:", dll.find(15))
dll.append(50)
dll.append(50, 8)
print(dll.to_list()) # Output: [30, 15, 10, 50]