#0181

Course Schedule: Can Finish

MediumDSA25 min20 XP

Problem

Given num_courses and prerequisites [course, prerequisite], return True if all courses can be completed.

Why This Matters

Dependency graphs appear in courses, package managers, build systems, and workflow schedulers.

Function Signature

def can_finish(num_courses, prerequisites):

Examples

Example 1

Inputnum_courses = 4, prerequisites = [[1,0],[2,1],[3,2]]

OutputTrue

There is a valid order: 0, 1, 2, 3.

Constraints

Return the exact requested result.
Handle common edge cases.
Keep the solution readable before optimizing.

CodePython

def can_finish(num_courses, prerequisites):
    """
    Input example: num_courses = 4, prerequisites = [[1,0],[2,1],[3,2]]
    Return: True
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return False

def can_finish(num_courses, prerequisites):
    """
    Input example: num_courses = 4, prerequisites = [[1,0],[2,1],[3,2]]
    Return: True
    Return the value from the function so the tests can compare it. Do not print unless the prompt asks.
    """
    # write your code here
    return False

Visible browser tests run here when available.

Testcases1 visible / 3 hidden categories

Core example

Inputnum_courses = 4, prerequisites = [[1,0],[2,1],[3,2]]

ExpectedTrue

There is a valid order: 0, 1, 2, 3.

Hidden Test Categories

minimal inputrepeated valueslarger realistic input