Connected Components

flowchart TB
	0((0))
	1((1))
    2((2))
    3((3))
    4((4))
    1 --> 0
    1 --> 2
    3 --> 4

• Algorithm:
  1. Find the connected components that contain the node $s$ using BFS or DFS.
  2. Find a node $v$ (if any) in the graph that is not in any connected component found in step 1.
  3. Repeat step 1 with $v$ as the starting node.
• This algorithm runs in $O(n+m)$ time. (even though it may run BFS or DFS multiple times, it spends a constant amount of time on each edge and node)