Course Schedule Interval Minimization | Dataford Interview Questions

Given a course schedule problem with dependencies, find the minimum number of time intervals/rounds required to complete all courses.

Asked in the Phone Screen stage. Variation of LeetCode Course Schedule on CoderPad.

Problem

You are given n courses labeled 0 to n - 1 and a list of prerequisite pairs prerequisites, where each pair [a, b] means course b must be completed before course a can start. In one time interval, you may take any number of courses as long as all of their prerequisites have already been completed.

Return the minimum number of intervals needed to complete all courses, or -1 if it is impossible because the dependency graph contains a cycle.

Input

n: integer
prerequisites: list of pairs [a, b]

Output

Integer, the minimum number of rounds, or -1

Constraints

1 <= n <= 10^5
0 <= len(prerequisites) <= 2 * 10^5
0 <= a, b < n
Duplicate prerequisite pairs may appear

Function Signature

def min_rounds_to_finish_courses(n, prerequisites):

Your question is Course Schedule Interval Minimization. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.

Problem

Given a course schedule problem with dependencies, find the minimum number of time intervals/rounds required to complete all courses.

Asked in the Phone Screen stage. Variation of LeetCode Course Schedule on CoderPad.

Problem

Return the minimum number of intervals needed to complete all courses, or -1 if it is impossible because the dependency graph contains a cycle.

Input

n: integer
prerequisites: list of pairs [a, b]

Output

Integer, the minimum number of rounds, or -1

Constraints

1 <= n <= 10^5
0 <= len(prerequisites) <= 2 * 10^5
0 <= a, b < n
Duplicate prerequisite pairs may appear

Function Signature

def min_rounds_to_finish_courses(n, prerequisites):

Your question is Course Schedule Interval Minimization. Start with the requirements in the Question tab.

Run and submit as often as you like. When you're ready, talk me through your approach or go straight to the code.