![Void BFS(vertex u)
{
initialize queue Q;
visited[u]=1;
enqueue(u,Q);
while(!isempty)
{
u= Dequeue(Q)
print u
for all vertices v adjacent to u do
if (visited[v]==0) then
{
Enqueue(v,Q)
visited[v]=1;
}
}
}](https://image.slidesharecdn.com/unitiv-210520091315/85/DS-Graph-Traversal-4-320.jpg)
![Routine for DFS
Void DFS(Vertex V)
{
visited[V]=True;
for each W adjacent to V
if (! Visited[W])
DFS(W);
}](https://image.slidesharecdn.com/unitiv-210520091315/85/DS-Graph-Traversal-8-320.jpg)
DS - Graph Traversal
- 1. Graph traversal •A graph traversal is a systematic way of visiting the nodes in a specific order •Types •Depth first traversal •Breadth first traversal
- 2. Breadth first traversal(BFS) • Graph G starts from an unvisited vertex u • Then all unvisited vertices vi adjacent to u are visited and then all unvisited vertices wj adjacent to vj are visited and so on
- 3. • Choose any node in the graph designate it as the search node & mark it as visited • Using the adjacency matrix of the graph, find all the unvisited adjacent nodes to the search node and enqueue them into the queue Q • Then the search node is dequeued from the queue. Mark that node as visited and select the new search node • Repeat step 2 & 3 using the new search node
- 4. Void BFS(vertex u) { initialize queue Q; visited[u]=1; enqueue(u,Q); while(!isempty) { u= Dequeue(Q) print u for all vertices v adjacent to u do if (visited[v]==0) then { Enqueue(v,Q) visited[v]=1; } } }
- 5. applications • To check whether the graph is connected or not
- 6. Depth first search • Depth first search works by selecting one vertex V of G as a start vertex • V is marked visited • Then each unvisited vertex adjacent to V is searched using depth first search recursively • This process continues until a dead end / no adjacent unvisited vertices is encountered
- 7. 1. Choose any node in the graph. Designate it as the search node and mark it as visited 2. Using the adjacency matrix of the graph, find a node adjacent to the search node that has not been visited yet. Designate this as the new search node and mark it as visited. 3. Repeat step 1 & 2 using the new search node
- 8. Routine for DFS Void DFS(Vertex V) { visited[V]=True; for each W adjacent to V if (! Visited[W]) DFS(W); }