DSA · Theory

Flatten Binary Tree to Sorted Linked List

Theory

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Flatten Binary Tree to Sorted Linked List

Don’t start Flatten Binary Tree to Sorted Linked List with jargon. Start with a ticket queue node. That is the whole point.

Flatten Binary Tree to Sorted Linked List on the board: head → next → …. Then say what a ticket queue node looks like after.

Skip Flatten Binary Tree to Sorted Linked List and losing the next pointer on delete shows up in a counter.

Use Flatten Binary Tree to Sorted Linked List when a ticket queue node must stay clear. If a simpler DSA step works, use that instead.

If a ticket queue node breaks under Flatten Binary Tree to Sorted Linked List, check losing the next pointer on delete first.

Flatten Binary Tree to Sorted Linked List is not a lonely heading. Kabir ties it to a ticket queue node.

Viva for Flatten Binary Tree to Sorted Linked List: 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 Flatten Binary Tree to Sorted Linked List. 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

Flatten Binary Tree to Sorted Linked List — a linked list chains nodes with next pointers instead of contiguous indexes.

Short notes

DefFlatten Binary Tree to Sorted Linked List — Kabir uses it for a ticket queue node in a counter.
RuleFlatten Binary Tree to Sorted Linked List → head → next → ….
RememberFlatten Binary Tree to Sorted Linked List + time vs memory (a counter).
UseFlatten Binary Tree to Sorted Linked List in a counter (a ticket queue node).
TrapFlatten Binary Tree to Sorted Linked List — losing the next pointer on delete.
ExFlatten Binary Tree to Sorted 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

Flatten Binary Tree to Sorted Linked List

Example

Short notes

Questions

Flatten Binary Tree to Sorted Linked List

Example

Short notes

Questions