Queue interview questions

Buffer bursty streamed text and emit it one character at a time at a steady cadence, with flush and stop controls.

Build a double-ended queue with constant-time push and pop at both the front and the back, backed by a doubly linked list.

Queue writes while offline and flush them in FIFO order when the network returns, retrying failures without dropping or reordering.

Build a FIFO queue out of two LIFO stacks — pour one stack into the other so the reversed order dequeues oldest-first in amortized constant time.