队列
- A queue means to line up for something.
- Queues use the First In First Out (FIFO) system. Rather than piling items up, the longest one in the queue will be popped.
- Insertions are made at the rear of the queue.
- Deletions take place at the front of the queue.
- So the last one added is always the last one available for deletion
- Let 𝒏 be the number of elements in the queue
- The space used is 𝑶(𝒏)
- Each operation runs in time 𝑶(𝟏)
双端队列
Deque, a double ended queue
- You can insert items at either end and delete them at either end
- There is no longer a front and rear, simply a front and rear, simply 2 ends.
