First year of AH, so be gentle with me it’s been a while since I had to think about these.
The question has the Front at 3 and the rear at 6, does that mean that the queue is 3,4,5,6? With locations 4&5 being empty? can the queue go 3,2,1,0,6 ? this appears to be what the question is suggesting. So Join 56 would put add on at location 5 and Join 35 at location 4. Leave would move the front to 2, giving the answer 7 that they are looking for in 3.1 and Front 1, rear 4 in 3.2
I had a look on the notes and on a couple of those pages and they all have the stacks increasing so an example like
Could have a start at 1 and end at 4 while
Would be start 3, end 0
Can anyone shed some light on it for me?