1. Consider the following directed graph:

The number of different topological ordering of the vertices of the graph is- Option : C
- Explanation :

The most efficient algorithm for finding the number of connected components (articulation point) in an undirected graph on n vertices and n edges using depth-first search takes O(m + n) time.Assume n ≤ m

- Option : B
- Explanation :

Usinng BFS traversal we can set the twin pointer in each entry in each adjacency list. So it will take O(m + n) time.