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# directed and undirected graph in data structure

Imagine graphs as a set of pumps( the circles) which can send liquid to others when are connected.In directed graphs the arrow show from where it comes and where the liquid (data) goes and in undirected graph it goes from both ways.Also a directed graph can have multiple arrows between two vertices(the pumps ) depending always on the graph. In Undirected Graph have unordered pair of edges.In Directed Graph, each edge(E) will be associated with directions.So, directed Graph … Graphs are represented by the edges between the nodes. The connecting edges can be considered directed or undirected. Mixed Graph: A graph with undirected and directed edges is said to be a mixed graph. A graph in which the edges do not have directions is called the Undirected graph. Quantifying the Graph Degree of a Vertex. There are other graphs that aren't complete, and have fewer edges than the complete graph. An Edge is also known as Arc. Basic Terminology in a graph. A graph can be defined as a collection of Nodes which are also called “vertices” and “edges” that connect two or more vertices. PolyTree is a directed graph without any undirected cycles. Adjacency list associates each vertex in the graph with the collection of its neighboring vertices or edges. Graph in data structure 1. When writing test questions, the connection matrix generally has a large memory redundancy, so adjacency table is generally used. Vertex: An individual data element of a graph is called Vertex. Directed And Undirected Graph. Edge: An edge is a connecting link between two vertices. A graph G is defined as follows: G=(V,E) V(G): a finite, nonempty set of vertices E(G): a set of edges (pairs of vertices) 2Graph Origin: If an edge is directed, its first endpoint is said to be the origin of it. Degree of vertex is the number of lines associated with it. In general, the space for the adjacency list representation is \$\Theta(V+E)\$; this fact holds for all graphs, regardless of how many edges they have. Forest is a undirected graph without any cycles. Indeed, in undirected graph, if there is an edge (2, 5) then there is also an edge (5, 2). This is also the reason, why there are two cells for every edge in the sample. A Graph is a collection of Vertices(V) and Edges(E). If the connecting edges in a graph are undirected, then the graph is called an undirected graph, and if the connecting edges in a graph are directed, then it is called a directed graph. PolyTree. Referred by its short name DAG. Given an undirected or a directed graph, implement graph data structure in C++ using STL. Graphs A data structure that consists of a set of nodes (vertices) and a set of edges that relate the nodes to each other The set of edges describes relationships among the vertices . Forest. An undirected graph is shown in the above figure since its edges are not attached with any of the directions. However, in an undirected graph, edges are not associated with the directions with them. Loops, if they are allowed in a graph, correspond to the diagonal elements of an adjacency matrix. A graph can be directed or undirected. Implement for both weighted and unweighted graphs using Adjacency List representation of the graph. Directed graphs are more informative than corresponding undirected graphs when the network is sparse. An undirected graph simply represents edges as lines between the nodes. So it is divided into directed graph and undirected graph; The storage structure of graphs generally includes adjacency matrix and adjacency table. A directed acyclic graph is directed graph without any directed cycles. Data Structure Graph 2. A graph is a non-linear data structure. 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