DSA · Theory

Priority Queue using Linked list

Theory

157/810

Priority Queue using Linked list

Priority Queue using Linked list is a DSA topic. In plain words you use it for a ticket queue node in a counter. Don’t start with a slogan — start with that picture.

Smallest example: head → next → …. Type it, run it, and say what you see. If you can do that from memory, you know Priority Queue using Linked list.

From the example next to this theory — Priority Queue using Linked list — queue is FIFO.

Trap — losing the next pointer on delete. Fix that before you talk about advanced DSA.

Viva — what is Priority Queue using Linked list? Then show head → next → …. Then name the trap.

Diagram

  front → [A][B][C] ← rear
  out ↑         ↑ in
       FIFO

Exam tip

What is Priority Queue using Linked list? Show this: head → next → …. Trap: losing the next pointer on delete.

Example

from collections import deque

q = deque()
q.append(10)      # enqueue
q.append(20)
print(q.popleft())  # 10
print(list(q))

Priority Queue using Linked list — queue is FIFO. deque.popleft() is O(1).

Short notes

DefPriority Queue using Linked list — a ticket queue node in a counter.
Rulehead → next → …
Traplosing the next pointer on delete
Usea counter

DSA · Theory

Priority Queue using Linked list

← All stacks

Theory

157/810

Priority Queue using Linked list

Priority Queue using Linked list is a DSA topic. In plain words you use it for a ticket queue node in a counter. Don’t start with a slogan — start with that picture.

Smallest example: head → next → …. Type it, run it, and say what you see. If you can do that from memory, you know Priority Queue using Linked list.

From the example next to this theory — Priority Queue using Linked list — queue is FIFO.

Trap — losing the next pointer on delete. Fix that before you talk about advanced DSA.

Viva — what is Priority Queue using Linked list? Then show head → next → …. Then name the trap.

Diagram

  front → [A][B][C] ← rear
  out ↑         ↑ in
       FIFO

Exam tip

What is Priority Queue using Linked list? Show this: head → next → …. Trap: losing the next pointer on delete.

Example

from collections import deque

q = deque()
q.append(10)      # enqueue
q.append(20)
print(q.popleft())  # 10
print(list(q))

Priority Queue using Linked list — queue is FIFO. deque.popleft() is O(1).

Short notes

DefPriority Queue using Linked list — a ticket queue node in a counter.
Rulehead → next → …
Traplosing the next pointer on delete
Usea counter

Priority Queue using Linked list

Example

Short notes

Questions

Priority Queue using Linked list

Example

Short notes

Questions