Course Schedule With Cycle Detection

Solve a course schedule scheduling problem using graph-based algorithms to detect cycles and determine the correct order of completion. Implement find_order(num_courses, prerequisites), where each prerequisite pair [course, prerequisite] means the prerequisite must be completed first. Return any valid course order, or [] if no valid order exists because the dependency graph contains a cycle. num_courses is an integer, and prerequisites is a list of integer pairs.