Code Room
CodingMediumcod-g1463
Subject IntervalsLevel Entry–Mid~15 minCommon in Algorithms & data structures interviewsIndustries Software development

Question

You are given an unsorted list of busy intervals [start, end] — each occupying the half-open span [start, end) with nonnegative integer bounds — and a required duration d >= 1. Return the earliest nonnegative start time t such that the span [t, t + d) does not intersect any busy interval. Example: busy [[0,5],[7,9]] with d = 2 gives 5, since [5, 7) fits exactly between them.

Implement
earliest_free_slot(busy: list[list[int]], d: int) → int
Examples
in[[[0,5],[7,9]],2]out5
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.