Evaluate arithmetic expression without using extra stack
Company: Meta
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: Medium
Interview Round: Technical Screen
Write a function to evaluate a string expression consisting of non-negative integers and the operators +, -, *, and / (integer division truncates toward zero). Process the string in one left-to-right pass in O(n) time and O(
1) extra space—do not use a stack or recursion. Explain how you track the last term and aggregated result to handle operator precedence without auxiliary data structures, and analyze edge cases like spaces and multi-digit numbers.
Quick Answer: This question evaluates a candidate's ability to perform in-place arithmetic expression evaluation, focusing on string parsing, handling multi-digit numbers and whitespace, operator precedence, integer division semantics, and designing O(n) time with O(1) extra space solutions in the Coding & Algorithms domain.