Optimize file reading and expression DFS
Company: Instacart
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: Medium
Interview Round: HR Screen
##### Question
Given a large password file, build a program to read the required password(s) while minimizing memory usage. How would you optimize the space so that only the needed content is loaded? Given a mathematical expression as a string, write code to evaluate it using a depth-first-search (DFS) approach.
Quick Answer: This question evaluates proficiency in memory-efficient file I/O and streaming data access alongside parsing and evaluating mathematical expressions using depth-first search, testing parsing algorithms, recursion/stack reasoning, and space-time trade-offs.