210. Course Schedule II

解題說明

C++ 解法

複雜度分析

虛擬碼

1. Build adjacency list adj[] and indegree[] array from prerequisites
   - For each [course, prereq]: adj[prereq].append(course), indegree[course]++
2. Initialize BFS queue with all nodes where indegree[i] == 0
3. While queue is not empty:
   a. Dequeue node, append to order[]
   b. For each neighbor of node:
      - Decrement indegree[neighbor]
      - If indegree[neighbor] == 0: enqueue neighbor
4. If len(order) == numCourses: return order
5. Else: return [] (cycle detected)

其他解法

延伸思考