Code Room
CodingMediumcod-g624
Subject String parsingLevel Entry–Mid~22 minCommon in Algorithms & data structures interviewsIndustries Telecom, Software development

Question

Given a string of only digits, return all possible valid IPv4 addresses that can be formed by inserting three dots, in ascending lexicographic order. Each of the four octets must be 0-255 with no leading zeros (a single '0' is allowed). 0 <= len(s) <= 12. Example: '25525511135' -> ['255.255.11.135','255.255.111.35'].

Implement
restore_ip_addresses(s: str) → list[str]
Examples
in["25525511135"]out["255.255.11.135","255.255.111.35"]
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.

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.