**Problem Statement:**
Given the required input arguments, write an efficient algorithm to solve the **Course Schedule II (Topo Sort Order)** problem. Implement the required logic as specified by standard definitions for this classic algorithmic challenge.
**Hint / Expected Approach:**
Kahn's BFS: queue nodes with in-degree 0
**Edge Cases to Consider:**
- (1) No valid ordering (cycle)
- (2) No prerequisites (any order)
- (3) Linear dependency chain