Question
Two delivery drivers log their shifts for the week as minute intervals [start, end], each occupying the half-open span [start, end). Each driver's own shifts never overlap, but the lists are unsorted. Return the total number of minutes during which both drivers were on duty at the same time. Example: driver A [[0,60],[120,180]] and driver B [[30,150]] share 60 minutes.
shared_on_duty_minutes(a: list[list[int]], b: list[list[int]]) → int[[[0,60],[120,180]],[[30,150]]]out60State 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.