linked list i python code example

Example 1: linked list python example

class Node:
    def __init__(self, data=None):
        self.data = data
        self.next = None

class SLinkedList:
    def __init__(self):
        self.head = None

    def Atbegining(self, data_in):
        NewNode = Node(data_in)
        NewNode.next = self.head
        self.head = NewNode
		
# Function to remove node
    def RemoveNode(self, Removekey):

        HeadVal = self.head

        if (HeadVal is not None):
            if (HeadVal.data == Removekey):
                self.head = HeadVal.next
                HeadVal = None
                return

        while (HeadVal is not None):
            if HeadVal.data == Removekey:
                break
            prev = HeadVal
            HeadVal = HeadVal.next

        if (HeadVal == None):
            return

        prev.next = HeadVal.next

        HeadVal = None

    def LListprint(self):
        printval = self.head
        while (printval):
            print(printval.data),
            printval = printval.next


llist = SLinkedList()
llist.Atbegining("Mon")
llist.Atbegining("Tue")
llist.Atbegining("Wed")
llist.Atbegining("Thu")
llist.RemoveNode("Tue")
llist.LListprint()

Example 2: doubly linked list python

class ListNode:
    def __init__(self, value, prev=None, next=None):
        self.prev = prev
        self.value = value
        self.next = next

class DoublyLinkedList:
    def __init__(self, node=None):
        self.head = node
        self.tail = node
        self.length = 1 if node is not None else 0

    def __len__(self):
        return self.length
   
  	def add_to_head(self, value):
        new_node = ListNode(value, None, None)
        self.length += 1
        if not self.head and not self.tail:
            self.head = new_node
            self.tail = new_node
        else:
            new_node.next = self.head
            self.head.prev = new_node
            self.head = new_node
 
    def remove_from_head(self):
        value = self.head.value
        self.delete(self.head)
        return value

    def add_to_tail(self, value):
        new_node = ListNode(value, None, None)
        self.length += 1
        if not self.tail and not self.head:
            self.tail = new_node
            self.head = new_node
        else:
            new_node.prev = self.tail
            self.tail.next = new_node
            self.tail = new_node
            

    def remove_from_tail(self):
        value = self.tail.value
        self.delete(self.tail)
        return value
            
    def move_to_front(self, node):
        if node is self.head:
            return
        value = node.value
        if node is self.tail:
            self.remove_from_tail()
        else:
            node.delete()
            self.length -= 1
        self.add_to_head(value)
        
    def move_to_end(self, node):
        if node is self.tail:
            return
        value = node.value
        if node is self.head:
            self.remove_from_head()
            self.add_to_tail(value)
        else:
            node.delete()
            self.length -= 1
            self.add_to_tail(value)

    def delete(self, node):
        self.length -= 1
        if not self.head and not self.tail:
            return
        if self.head == self.tail:
            self.head = None
            self.tail = None
        elif self.head == node:
            self.head = node.next
            node.delete()
        elif self.tail == node:
            self.tail = node.prev
            node.delete()
        else:
            node.delete()

    def get_max(self):
        if not self.head:
            return None
        max_val = self.head.value
        current = self.head
        while current:
            if current.value > max_val:
                max_val = current.value
            current = current.next
        return max_val