Code RoomFrequency stack
HardPrep Room Coding #1338

Frequency stack

CodingAlgorithms & data structuresSenior–Staff~35 min

Implement a FreqStack: push(x) adds a value; pop() removes and returns the most frequent value, breaking ties by the one pushed most recently (closest to top). Simulate a sequence of operations: each op is ['push', x] or ['pop']. Return the list of values returned by each 'pop'.

Implement
freq_stack(ops: list[list]) → list[int]
Examples
in[[["push",5],["push",7],["push",5],["push",7],["push",4],["push",5],["pop"],["pop"],["pop"],["pop"]]]out[5,7,5,4]
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.

0:00 of about 35 min
InputExpectedGot
[[["push",5],["push",7],["push",5],["push",7],["push",4],["push",5],["pop"],["pop"],["pop"],["pop"]]][5,7,5,4]not run yetsample