Stack Implementation | Dataford Interview Questions

Stack Implementation

EasyPython

Problem

A 24]7.ai conversation workflow needs a last-in, first-out history of event identifiers so the most recent event can be inspected or removed first. Implement the stack behavior for a sequence of operations.

Create a function that processes operations in order:

push(value) adds value to the top of the stack and produces no output.
pop() removes and returns the top value.
top() returns the top value without removing it.

The input is represented as a list of operation arrays. A push operation has the form ["push", value]; pop and top operations have the form ["pop"] and ["top"]. Return a list containing results from pop and top operations in their original order. Do not include output for push operations.

Formal Specification

Given operations, a list of operation arrays containing integer values, return a list of integers produced by pop and top. The input guarantees that pop and top are never called when the stack is empty.

Constraints

1 <= len(operations) <= 10^5
Values are integers in [-10^9, 10^9]
Every operation is valid
The operation name is one of push, pop, or top

Function Signature

def process_stack(operations):

Create a function that processes operations in order:

push(value) adds value to the top of the stack and produces no output.
pop() removes and returns the top value.
top() returns the top value without removing it.