The traversal algorithm of graphs

1. Width-First search (BFS) (1) algorithm ideas for connected graphs
Preparation: Beginning V and an empty queue Q.
① will mark V with an access tag. And put v into the queue Q.
② Remove Queue Q's first element U. Searches for all vertices adjacent to U. If w is adjacent to U and is not interviewed, then W is flagged. And put W into the queue Q.
③ repeatedly ②. Until the queue q is empty

(2) Algorithm code:
(3) Complexity analysis

(4) Width first spanning tree
2, the general figure of the width of the first traversal
3. Depth-first search for connected graphs (DFS)

(3) Depth-first spanning tree

The traversal algorithm of graphs