Evaluate expression without stack, constant space
Company: Meta
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: Medium
Interview Round: Technical Screen
Given a string s representing a valid arithmetic expression containing non-negative integers, '+', '-', '*', '/', and spaces (no parentheses), evaluate and return its value. Implement a single-pass solution in O(n) time using O(
1) extra space; you may not use an explicit stack. Division should truncate toward zero. Explain how you handle multi-digit numbers and operator precedence without a stack.
Quick Answer: This question evaluates a candidate's ability to parse and evaluate arithmetic expressions using constant extra space, covering skills in string parsing, handling multi-digit numbers, operator precedence resolution, integer arithmetic semantics (including truncating division), and in-place algorithm design.