The document discusses four challenges related to queues: 1. The differences between stacks and queues in terms of their ordering (FILO vs FIFO) 2. Using diagrams to illustrate how queues work step-by-step using arrays, ring buffers, and double stacks 3. Determining whose turn it is in a queue-based system 4. Reversing the order of elements in a queue

1. Queue Challenges

2. Challenge 1: Stack vs. Queue
FILO
First In Last Out
FIFO
First In First Out

3. Challenge 2: Step-by-step Diagrams
Array
S W I F T
enqueue(“R”)
R
enqueue(“O”)
O
dequeue()enqueue(“C”)
C
dequeue()dequeue()enqueue(“K”)
K

4. Challenge 2: Step-by-step Diagrams
Ring buffer
I F T
Write
Read
queue3.enqueue("R") false
queue3.enqueue(“O") false
queue3.dequeue() “S”
queue3.enqueue(“C”) true
CS
queue3.dequeue() “W”
queue3.dequeue() “I”
queue3.enqueue(“K”) true
WK

5. S
Left Stack Dequeue Right Stack Enqueue
enqueue(“R”)
Challenge 2: Step-by-step Diagrams
Double stack
W
F
T
I
R
O
enqueue(“O”)dequeue()enqueue(“C”)
C
dequeue()dequeue()
K
enqueue(“K”)

6. Challenge 3: Whose turn is it?

7. Challenge 4: Reverse Queue