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Quicksort on Doubly Linked List

Theory

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Quicksort on Doubly Linked List

Quicksort on Doubly Linked List sits in a counter. Riya’s job is a ticket queue node. Write that first.

For Quicksort on Doubly Linked List, time vs memory is in play. Don’t blame it until you have traced a ticket queue node.

Quicksort on Doubly Linked List exists so Riya can keep a ticket queue node correct in a counter.

Use Quicksort on Doubly 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 Quicksort on Doubly Linked List, check losing the next pointer on delete first.

Quicksort on Doubly Linked List is not a lonely heading. Riya ties it to a ticket queue node.

Close Quicksort on Doubly Linked List with: “If I skip it, a ticket queue node goes wrong like this: losing the next pointer on delete.”

Diagram

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

Exam tip

Board: a ticket queue node. Dry-run Quicksort on Doubly Linked List. Name the trap: losing the next pointer on delete.

Example

def quick_sort(arr):
    if len(arr) <= 1:
        return arr
    pivot = arr[len(arr) // 2]
    left = [x for x in arr if x < pivot]
    mid = [x for x in arr if x == pivot]
    right = [x for x in arr if x > pivot]
    return quick_sort(left) + mid + quick_sort(right)

print(quick_sort([5, 1, 4, 2, 3]))

Quicksort on Doubly Linked List — quick sort partitions around a pivot, then sorts both sides.

Short notes

DefQuicksort on Doubly Linked List — Riya uses it for a ticket queue node in a counter.
RuleQuicksort on Doubly Linked List → head → next → ….
RememberQuicksort on Doubly Linked List + time vs memory (a counter).
UseQuicksort on Doubly Linked List in a counter (a ticket queue node).
TrapQuicksort on Doubly Linked List — losing the next pointer on delete.
ExQuicksort on Doubly Linked List → a ticket queue node.

def quick_sort(arr): if len(arr) <= 1: return arr pivot = arr[len(arr) // 2] left = [x for x in arr if x < pivot] mid = [x for x in arr if x == pivot] right = [x for x in arr if x > pivot] return quick_sort(left) + mid + quick_sort(right) print(quick_sort([5, 1, 4, 2, 3]))

Quicksort on Doubly Linked List

Example

Short notes

Questions

Quicksort on Doubly Linked List

Example

Short notes

Questions