## What is semi connected?

A semi-connected graph is a graph that for each pair of vertices u,v, there is either a path from u to v or a path from v to u. Give an algorithm to test if a graph is semi-connected.

### How can you tell if a graph is semi connected?

If R_v != V(G), then run another DFS from v in G* and let the set of reachable nodes be R_v. If the union of R_v and R_v is not V(G) then the graph is not semi connected.

What does minimally connected mean?

Definition: A graph is said to be minimally connected if removal of any one edge from it disconnects the graph. Clearly, a minimally connected graph has no cycles.

What is 2 connected?

2-Connected Graphs. Definition 1. A graph is connected if for any two vertices x, y ∈ V (G), there is a path whose endpoints are x and y. A connected graph G is called 2-connected, if for every vertex x ∈ V (G), G − x is connected.

## What is unilaterally connected graph?

Unilaterally Connected: A graph is said to be unilaterally connected if it contains a directed path from u to v OR a directed path from v to u for every pair of vertices u, v. Hence, at least for any pair of vertices, one vertex should be reachable form the other.

### What is a connected directed graph?

Directed graph connectivity A directed graph is weakly connected (or just connected) if the undirected underlying graph obtained by replacing all directed edges of the graph with undirected edges is a connected graph.

How do you test if a graph is connected?

Begin at any arbitrary node of the graph, G. Proceed from that node using either depth-first or breadth-first search, counting all nodes reached. Once the graph has been entirely traversed, if the number of nodes counted is equal to the number of nodes of G, the graph is connected; otherwise it is disconnected.

Are trees minimally connected?

Therefore, there is no circuit. Hence graph G is a tree. Conversely, let the graph G is a tree i.e; there exists one and only one path between every pair of vertices and we know that removal of one edge from the path makes the graph disconnected. Hence graph G is minimally connected.

## Can a tree be disconnected?

So a tree has the smallest possible number of edges for a connected graph. Any fewer edges and it will be disconnected. But of course, graphs with n-1 vertices can be disconnected.

### What is a singly connected graph?

In particular, we say a directed graph is singly connected if there existsat most one simple path between every pair of vertices. If there are two distinct simple paths connecting any two vertices, the graph is not singly connected. An undirected graph is singly connected if and only if it is a tree[2].

What is weakly connected digraph?

A digraph is weakly connected if when considering it as an undirected graph it is connected. I.e., for every pair of distinct vertices u and v there exists an undirected path (potentially running opposite the direction on an edge) from u to v.

What is weakly connected graph?

Given a directed graph, a weakly connected component (WCC) is a subgraph of the original graph where all vertices are connected to each other by some path, ignoring the direction of edges. In case of an undirected graph, a weakly connected component is also a strongly connected component.

## What does weakly connected mean?

Weakly Connected: A graph is said to be weakly connected if there doesn’t exist any path between any two pairs of vertices. Hence, if a graph G doesn’t contain a directed path (from u to v or from v to u for every pair of vertices u, v) then it is weakly connected.

### What does it mean if a graph is connected?

A graph is called connected if given any two vertices , there is a path from to . The following graph ( Assume that there is a edge from to. .) is a connected graph. Because any two points that you select there is path from one to another.

Is every tree connected?

In graph theory, a tree is an undirected graph in which any two vertices are connected by exactly one path, or equivalently a connected acyclic undirected graph….Tree (graph theory)

Trees
Chromatic number 2 if v > 1
Table of graphs and parameters

Is K1 connected?

According to Bogdán Zaválniji’s definition of connectivity, if we take any pair of vertices of a graph and there is path connecting them then the graph is connected. So, if we take K1, the only pair of vertices we can take is the single vertex v. But there is no path connecting v and v. So, how K1 is connected.

## What is a disconnected graph?

A graph is said to be disconnected if it is not connected, i.e., if there exist two nodes in such that no path in has those nodes as endpoints.