CodingMediumcod-g388

Subject StringsLevel Mid–Senior~25 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

Given two non-negative integers num1 and num2 represented as strings (no leading zeros except '0' itself, 1 <= len <= 200), return the product as a string. You must not convert the inputs to a language big-integer type or use built-in arbitrary-precision multiplication; implement the schoolbook algorithm.

Implement

string_multiply(num1: str, num2: str) → str

Examples

in["123","456"]out"56088"

What a strong answer looks like

State your approach and its time/space complexity out loud before you optimize. Handle the edge cases (empty input, duplicates, overflow), and say why you chose this over the brute force. Green tests are the floor, not the grade.

Learn the concepts

Vibe coding: describe the solution in plain language (or narrate it) and the coach grades your approach. Generating runnable code from your description is coming next.

Run or narrate your approach, then ask the coach.