Task scheduling semesters
There are n tasks labeled 0..n-1 and a list of prerequisite pairs [a, b] meaning b must be finished before a. Each semester you may take any number of tasks whose prerequisites are all already finished. Return the minimum number of semesters needed to finish all tasks, or -1 if a cycle makes it impossible. With no prerequisites everything can be done in one semester.
Implement
min_semesters(n: int, prereqs: list[list[int]]) → intExamples
in
[4,[[1,0],[2,0],[3,1],[3,2]]]out3What 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.
0:00 of about 25 min
solution.py
InputExpectedGot
[4,[[1,0],[2,0],[3,1],[3,2]]]3not run yetsample