DSA · Theory

Difference between Singly Linked List and Doubly Linked List

Theory

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Difference between Singly Linked List and Doubly Linked List

Don’t start Difference between Singly Linked List and Doubly Linked List with jargon. Start with a ticket queue node. That is the whole point.

Keep Difference between Singly Linked List and Doubly Linked List small. Rohit should finish a ticket queue node in a few lines, not a 40-line dump.

Skip Difference between Singly Linked List and Doubly Linked List and losing the next pointer on delete shows up in a counter.

Rohit ships Difference between Singly Linked List and Doubly Linked List in a counter. That is the use case worth saying.

Difference between Singly Linked List and Doubly Linked List miss: losing the next pointer on delete. Fix it before you talk about advanced DSA.

Place Difference between Singly Linked List and Doubly Linked List next to nearby DSA work — head → next → … is the link.

Viva for Difference between Singly Linked List and Doubly Linked List: what it is → head → next → … → the mistake (losing the next pointer on delete).

Diagram

  [10] → [20] → [30] → /
   head              tail

Exam tip

Say Difference between Singly Linked List and Doubly Linked List in one breath, then head → next → …, then losing the next pointer on delete.

Example

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

head = Node(1, Node(2, Node(3)))
cur = head
while cur:
    print(cur.val, end=" -> " if cur.next else "\n")
    cur = cur.next

Difference between Singly Linked List and Doubly Linked List — a linked list chains nodes with next pointers instead of contiguous indexes.

Short notes

DefDifference between Singly Linked List and Doubly Linked List — Rohit uses it for a ticket queue node in a counter.
RuleDifference between Singly Linked List and Doubly Linked List → head → next → ….
RememberDifference between Singly Linked List and Doubly Linked List + time vs memory (a counter).
UseDifference between Singly Linked List and Doubly Linked List in a counter (a ticket queue node).
TrapDifference between Singly Linked List and Doubly Linked List — losing the next pointer on delete.
ExDifference between Singly Linked List and Doubly Linked List → a ticket queue node.

class Node: def __init__(self, val, next=None): self.val = val self.next = next head = Node(1, Node(2, Node(3))) cur = head while cur: print(cur.val, end=" -> " if cur.next else "\n") cur = cur.next

Difference between Singly Linked List and Doubly Linked List

Example

Short notes

Questions

Difference between Singly Linked List and Doubly Linked List

Example

Short notes

Questions