## What is edge and vertex in graph?

In a diagram of a graph, a vertex is usually represented by a circle with a label, and an edge is represented by a line or arrow extending from one vertex to another. A vertex w is said to be adjacent to another vertex v if the graph contains an edge (v,w).

## What is node and edge in graph?

A Graph is a non-linear data structure consisting of nodes and edges. The nodes are sometimes also referred to as vertices and the edges are lines or arcs that connect any two nodes in the graph. For example, in Facebook, each person is represented with a vertex(or node).

## What is the edge set of a graph?

A graph consists of two finite sets, V and E. Each element of V is called a vertex (plural vertices). The elements of E, called edges, are unordered pairs of vertices.

## How do you find an edge set?

Let G=(V,E) be a graph. The set E of edges in G is called the edge set. It consists of (unordered) pairs of elements of the vertex set V. It is often convenient to refer to the edge set for a given graph G as E(G), especially if there is at any one time more than one graph under consideration.

## Is tree undirected graph?

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.

## How can you tell if an undirected graph is a tree?

In the case of undirected graphs, we perform three steps:

1. Perform a DFS check from any node to make sure that each node has exactly one parent. If not, return .
2. Check that all nodes are visited. If the DFS check wasn’t able to visit all nodes, then return .
3. Otherwise, the graph is a tree.

## What is undirected tree?

What is a undirected Tree?  An undirected graph Tree is one in which the pair of vertices in an edge is unordered .  An undirected graph is a tree if you know that any two of the following three properties are true:  It is connected  There are no cycles  There are n – 1 edges, where n is the number of nodes.

## How many edges are there in the complete graph?

Definition: A complete graph is a graph with N vertices and an edge between every two vertices. ▶ There are no loops. ▶ Every two vertices share exactly one edge.

## What is the number of edges in a graph K10?

Consider the graph K10, the complete graph with 10 vertices. 1. How many edges does this graph have? (Hint: Don’t try to draw the graph and count!) the handshake theorem, this is twice the number of edges, so there are 90/2 = 45 edges.)