Lecture 01-20-17

DFS

• DFS tree
• Runtime O(m + n)
  • “linear” for a graph
• Edges wrt tree
  • tree edges
    • edges visited while performing DFS
  • back edges
    • ancestors & descendants
  • cross edges
• No cross edges wrt dfs tree

BFS trees

• no edges that are back edges which are tree edges

Digraph

• Cross edges in DFS tree (of digraph)

Definitions

• articulation point:
  • v such that G\v is disconnected