Code Room
CodingMediumcod-g779
Subject Circular bufferLevel Entry–Mid~20 minCommon in Algorithms & data structures interviewsIndustries Software development, Telecom

Question

Implement a fixed-capacity circular buffer (ring) of size `cap`. Operations: ['enqueue', x] inserts at the rear and returns True, or False if full; ['dequeue'] removes from the front and returns the value, or None if empty; ['front'] returns the front value or None; ['rear'] returns the rear value or None. Given cap and an op list, return the list of results for enqueue/dequeue/front/rear (in op order). Use None for empty results.

Implement
circular_buffer(cap: int, ops: list[list]) → list
Examples
in[3,[["enqueue",1],["enqueue",2],["enqueue",3],["enqueue",4],["front"],["dequeue"],["enqueue",4],["rear"]]]out[true,true,true,false,1,1,true,4]
What a strong answer looks like

State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.

Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.

Run or narrate your approach, then ask the coach.