Evaluate arithmetic expression without parentheses
Company: Meta
Role: Software Engineer
Category: Coding & Algorithms
Difficulty: Medium
Interview Round: Onsite
Write evaluate(s: string) to compute the value of an arithmetic expression containing non-negative integers, '+', '-', '*', '/', and spaces, with operator precedence (* and / before + and -) and no parentheses. Division truncates toward zero. Aim for a single pass with O(
1) extra space beyond the output and a small stack or running registers. Discuss handling multi-digit numbers, consecutive spaces, and edge cases such as '3/2', '14-3/2', and trailing operators being invalid. Provide unit tests.
Quick Answer: This question evaluates a candidate's ability to parse and evaluate infix arithmetic expressions without parentheses, testing competency in expression parsing, operator precedence, multi-digit number handling, whitespace tolerance, integer division truncation, and edge-case validation.