The Impersonator

A medium Python interview practice problem on DataDriven. Write and execute real python code with instant grading.

Domain

Python

Difficulty

medium

Seniority

L5

Problem

Implement a FIFO queue backed by two stacks. Support enqueue(x), dequeue() (return value), peek() (return front). Test harness passes operations; returns parallel results: None for enqueue, the value for dequeue/peek.

Summary

You only have stacks. Make a queue anyway.

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