Singly Linked List (SLL)
Insertion
At Beginning:
New_node = Node(data)
New_node.next = head
Head = new_node
At Position (n):
Temp = head
For _ in range(n-1):
Temp = temp.next
New_node = Node(data)
New_node.next = temp.next
Temp.next = new_node
At End:
Temp = head
While temp.next:
Temp = temp.next
New_node = Node(data)
Temp.next = new_node
Deletion
At Beginning:
Head = head.next
At Position (n):
Temp = head
For _ in range(n-1):
Temp = temp.next
Temp.next = temp.next.next
At End:
Temp = head
While temp.next.next:
Temp = temp.next
Temp.next = None
Doubly Linked List (DLL)
Insertion
At Beginning:
New_node = Node(data)
New_node.next = head
Head.prev = new_node
Head = new_node
At Position (n):
Temp = head
For _ in range(n-1):
Temp = temp.next
New_node = Node(data)
New_node.next = temp.next
New_node.prev = temp
Temp.next.prev = new_node
Temp.next = new_node
At End:
Temp = head
While temp.next:
Temp = temp.next
New_node = Node(data)
Temp.next = new_node
New_node.prev = temp
Deletion
At Beginning:
Head = head.next
Head.prev = None
At Position (n):
Temp = head
For _ in range(n):
Temp = temp.next
Temp.prev.next = temp.next
Temp.next.prev = temp.prev
At End:
Temp = head
While temp.next:
Temp = temp.next
Temp.prev.next = None
Circular Linked List (CLL)
Insertion
At Beginning:
New_node = Node(data)
New_node.next = head
Temp = head
While temp.next != head:
Temp = temp.next
Temp.next = new_node
Head = new_node
At Position (n):
Temp = head
For _ in range(n-1):
Temp = temp.next
New_node = Node(data)
New_node.next = temp.next
Temp.next = new_node
At End:
Temp = head
While temp.next != head:
Temp = temp.next
New_node = Node(data)
Temp.next = new_node
New_node.next = head
Deletion
At Beginning:
Temp = head
While temp.next != head:
Temp = temp.next
Temp.next = head.next
Head = head.next
At Position (n):
Temp = head
For _ in range(n-1):
Temp = temp.next
Temp.next = temp.next.next
At End:
Temp = head
While temp.next.next != head:
Temp = temp.next
Temp.next = head
Singly Linked List – Node Creation
Class Node:
Def __init__(self, data):
Self.data = data
Self.next = None
Doubly Linked List – Node Creation
Class Node:
Def __init__(self, data):
Self.data = data
Self.next = None
Self.prev = None
Circular Linked List – Node Creation
Class Node:
Def __init__(self, data):
Self.data = data
Self.next = self # Points to itself in a circular list
Adding Objects (Nodes) at the End
Singly Linked List (SLL):
If head is None:
Head = Node(data)
Else:
Temp = head
While temp.next:
Temp = temp.next
Temp.next = Node(data)
Doubly Linked List (DLL):
If head is None:
Head = Node(data)
Else:
Temp = head
While temp.next:
Temp = temp.next
New_node = Node(data)
Temp.next = new_node
New_node.prev = temp
Circular Linked List (CLL):
If head is None:
Head = Node(data)
Else:
Temp = head
While temp.next != head:
Temp = temp.next
New_node = Node(data)
Temp.next = new_node
New_node.next = head
TEXT FORMAT LOGIC
1. Singly Linked List (SLL)
Insertion
At Beginning.
1. Create new node.
2. Point new node’s next to head.
3. Update head to new node.
At Position (n):
1. Traverse to (n-1)th node.
2. Create new node.
3. Point new node’s next to (n)th node.
4. Update (n-1)th node’s next to new node.
At End:
1. Traverse to last node.
2. Create new node.
3. Update last node’s next to new node.
Deletion
At Beginning:
1. Update head to head.next
At Position (n):
1. Traverse to (n-1)th node.
2. Update (n-1)th node’s next to (n+1)th node.
At End:
1. Traverse to second-last node.
2. Set second-last node’s next = None.
Doubly Linked List (DLL)
Insertion
At Beginning:
1. Create new node.
2. Point new node’s next to head.
3. Update head.prev to new node.
4. Update head to new node.
At Position (n):
1. Traverse to (n-1)th node.
2. Create new node.
3. Update new node’s next to (n)th node.
4. Update new node’s prev to (n-1)th node.
5. Adjust (n-1)th.next and (n)th.prev.
At End:
1. Traverse to last node.
2. Create new node.
3. Update last node’s next to new node.
4. Update new node’s prev to last node.
Deletion
At Beginning:
1. Update head to head.next.
2. Set head.prev = None.
At Position (n):
1. Traverse to (n)th node.
2. Update (n-1)th node’s next to (n+1)th node.
3. Update (n+1)th node’s prev to (n-1)th node.
At End:
1. Traverse to last node.
2. Update second-last node’s next = None.
3. Circular Linked List (CLL)
Insertion
At Beginning:
1. Create new node.
2. Point new node’s next to head.
3. Traverse to last node and update last.next to new node.
4. Update head to new node.
At Position (n):
1. Traverse to (n-1)th node.
2. Create new node.
3. Update new node’s next to (n)th node.
4. Update (n-1)th node’s next to new node.
At End:
1. Traverse to last node.
2. Create new node.
3. Update last node’s next to new node.
4. Point new node’s next to head.
Deletion
At Beginning:
1. Traverse to last node.
2. Update last.next to head.next.
3. Update head to head.next.
At Position (n):
1. Traverse to (n-1)th node.
2. Update (n-1)th node’s next to (n+1)th node.
At End:
1. Traverse to second-last node.
2. Update second-last node’s next to head.
