DSA · Theory

Find out the person who got the ticket last problem in queue

Theory

588/810

If you can teach Find out the person who got the ticket last problem in queue using print jobs, you know it. If you only know the heading, you don’t.

Find out the person who got the ticket last problem in queue on the board: enqueue / dequeue FIFO. Then say what print jobs looks like after.

Without Find out the person who got the ticket last problem in queue, a lab printer gets messy and print jobs is hard to trust.

Priya ships Find out the person who got the ticket last problem in queue in a lab printer. That is the use case worth saying.

Find out the person who got the ticket last problem in queue miss: confusing front and rear. Fix it before you talk about advanced DSA.

After Find out the person who got the ticket last problem in queue, Priya should still remember confusing front and rear.

Viva for Find out the person who got the ticket last problem in queue: what it is → enqueue / dequeue FIFO → the mistake (confusing front and rear).

Diagram

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

Exam tip

Say Find out the person who got the ticket last problem in queue in one breath, then enqueue / dequeue FIFO, then confusing front and rear.

from collections import deque

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

Find out the person who got the ticket last problem in queue — queue is FIFO. deque.popleft() is O(1).

DefFind out the person who got the ticket last problem in queue — Priya uses it for print jobs in a lab printer.
RuleFind out the person who got the ticket last problem in queue → enqueue / dequeue FIFO.
RememberFind out the person who got the ticket last problem in queue + Big-O (a lab printer).
UseFind out the person who got the ticket last problem in queue in a lab printer (print jobs).
TrapFind out the person who got the ticket last problem in queue — confusing front and rear.
ExFind out the person who got the ticket last problem in queue → print jobs.