SingleLinkedList with basic operations

01. DataStructures/01. Linked List/1. Singly-Linked-List/Basic Operations/SinglyLL.py

@@ -1,65 +1,136 @@
-# A simple Python program to introduce a linked list
-
-class Node:
-
- # Function to initialise the node object
- def __init__(self, data):
- self.data = data # Assign data
- self.next = None # Initialize next as null
-
-
-# Linked List class contains a Node object
-class LinkedList:
-
- # Function to initialize head
- def __init__(self):
- self.head = None
-
-
-# Code execution starts here
-if __name__=='__main__':
-
- # Start with the empty list
- llist = LinkedList()
-
- llist.head = Node(1)
- second = Node(2)
- third = Node(3)
-
-
- llist.head.next = second; # Link first node with second
- second.next = third; # Link second node with the third node
-
-
-
-# Node class
+## A Python Program to implement SingleLinkedList
+
+## Creation of Node Class to create node object ## 
+
 class Node:
+ def __init__(self,value=None):
+ self.value = value
+ self.next = None
+
+## SingleLinkedList Class
+class singleLinkList:
 
- # Function to initialise the node object
- def __init__(self, data):
- self.data = data # Assign data
- self.next = None # Initialize next as null
-
-
-# Linked List class contains a Node object
-class LinkedList:
-
- # Function to initialize head
  def __init__(self):
- self.head = None
-
-
-# Code execution starts here
-if __name__=='__main__':
-
- # Start with the empty list
- llist = LinkedList()
-
- llist.head = Node(1)
- second = Node(2)
- third = Node(3)
-
-
- llist.head.next = second; # Link first node with second
- second.next = third; # Link second node with the third node
-
+ self.head=None
+ self.tail=None
+
+ ## To Iterate through nodes and print node 
+ def __iter__(self):
+ node = self.head
+ while node:
+ yield node
+ node = node.next
+
+
+ ### Inserting Function ###
+ def insertNode(self,value,location):
+ newNode = Node(value)
+ if self.head is None:
+ self.head = newNode
+ self.tail = newNode
+ else:
+ if location == 0 : ## location 0 means beginning position
+ newNode.next = self.head
+ self.head = newNode
+ elif location == 1 : ## location 1 means last position
+ newNode.next = None
+ self.tail.next = newNode
+ self.tail = newNode
+ else :
+ currentNode = self.head
+ index = 0 
+ while index < location-1:
+ currentNode = currentNode.next
+ index+=1
+ nextNode = currentNode.next
+ currentNode.next = newNode
+ newNode.next = nextNode
+
+
+ ## Looping thorugh nodes 
+ def traverse(self):
+ if self.head is None:
+ print('Single Linked List does not exist')
+ else:
+ node = self.head
+ while node is not None:
+ print(node.value)
+ node=node.next
+
+
+ ## Search a Node value exist or not 
+ def search(self,value):
+ node = self.head
+ if self.head is None:
+ print('No nodes present in list')
+ else:
+ node = self.head
+ while node is not None:
+ if node.value==value:
+ return f"{value} is exist in list"
+ node=node.next
+ return f"{value} Value does not exist"
+
+ ## Delete the node from end or beginning or after a node 
+ def delete(self,location):
+ if self.head == None:
+ print('List does not exist')
+ else:
+ if location == 0 :
+ if self.head == self.tail:
+ self.head=None
+ self.tail=None
+ else:
+ self.head=self.head.next
+ elif location == 1 :
+ if self.head == self.tail:
+ self.head=None
+ self.tail=None
+ else:
+ node = self.head
+ while node is not None:
+ if node.next == self.tail:
+ break
+ node=node.next
+ node.next=None
+ self.tail=node
+ else:
+ currentNode = self.head
+ index=0
+ while index < location-1:
+ currentNode = currentNode.next
+ index+=1
+ nextNode = currentNode.next
+ currentNode.next=nextNode.next
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+
+## Initialising the SingleLinkedList Object 
+sll = singleLinkList()
+
+## Through list object we are performing various functions using methods in class
+## Node Object Initailised through methods in SingleLinkedList Class 
+sll.insertNode(1,0)
+sll.insertNode(5,1)
+sll.insertNode(3,2)
+sll.insertNode(9,3)
+sll.insertNode(4,4)
+sll.traverse()
+print(sll.search(5))
+print(sll.search(9))
+print(sll.search(8))
+sll.delete(3)
+## __iter__ helps to retrive list of nodes in following way
+print([node.value for node in sll])