DSA · Theory

Reverse a Linked List in Groups of Given Size

Theory

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Reverse a Linked List in Groups of Given Size

Reverse a Linked List in Groups of Given Size is a DSA idea you prove with a ticket queue node, not with a slogan.

Reverse a Linked List in Groups of Given Size order: meaning → head → next → … → one limit. Dumping ten features helps nobody.

Reverse a Linked List in Groups of Given Size exists so Farhan can keep a ticket queue node correct in a counter.

Farhan ships Reverse a Linked List in Groups of Given Size in a counter. That is the use case worth saying.

Don’t do this with Reverse a Linked List in Groups of Given Size: losing the next pointer on delete. Interviewers spot it in ten seconds.

Place Reverse a Linked List in Groups of Given Size next to nearby DSA work — head → next → … is the link.

Viva for Reverse a Linked List in Groups of Given Size: what it is → head → next → … → the mistake (losing the next pointer on delete).

Diagram

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

Exam tip

Board: a ticket queue node. Dry-run Reverse a Linked List in Groups of Given Size. Name the trap: 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

Reverse a Linked List in Groups of Given Size — a linked list chains nodes with next pointers instead of contiguous indexes.

Short notes

DefReverse a Linked List in Groups of Given Size — Farhan uses it for a ticket queue node in a counter.
RuleReverse a Linked List in Groups of Given Size → head → next → ….
RememberReverse a Linked List in Groups of Given Size + time vs memory (a counter).
UseReverse a Linked List in Groups of Given Size in a counter (a ticket queue node).
TrapReverse a Linked List in Groups of Given Size — losing the next pointer on delete.
ExReverse a Linked List in Groups of Given Size → 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

Reverse a Linked List in Groups of Given Size

Example

Short notes

Questions

Reverse a Linked List in Groups of Given Size

Example

Short notes

Questions