Explicit descriptions Descriptions of vertex set and edge set. 1. If H is either an edge or K4 then we conclude that G is planar. As a consequence, a claw-free graph G is hamiltonian if and only if G+uv is hamiltonian, where u, u is a K4-pair. The hamiltonian path graph H(F) of a graph F is that graph having the same vertex set as F and in which two vertices u and v are adjacent if and only if F contains a hamiltonian u − v path. If you label 0 and 2 as "A", and 1 and 3 as "B", you can see that the graph connects only A's to B's, and not A's to A's or B's to B's. Based on these results we define socalled K4-closures of G. We give infinite classes of graphs with small maximum degree and large diameter, and with many vertices of degree two having complete K4-closures. Definition. Hamiltonian Path Examples- Examples of Hamiltonian path are as follows- Hamiltonian Circuit- Hamiltonian circuit is also known as Hamiltonian Cycle.. A complete graph K4. The complete graph with 4 vertices is written K4, etc. Vertex set: Edge set: Hamiltonian graph - A connected graph G is called Hamiltonian graph if there is a cycle which includes every vertex of G and the cycle is called Hamiltonian cycle. . This graph, denoted is defined as the complete graph on a set of size four. As a consequence, a claw-free graph G is hamiltonian if and only if G+uv is hamiltonian, where u,v is a K4-pair. 2. H is non separable simple graph with n 5, e 7. 1. K3 has 6 of them: ABCA, BCAB, CABC and their mirror images ACBA, BACB, CBAC. Every complete graph has a Hamilton circuit. This observation and Proposition 1.1 imply Proposition 2.1. Based on these results we define socalled K4-closures of G. We give infinite classes of graphs with small maximum degree and large diameter, and with many vertices of degree two having complete K4-closures. 3. The graph is clearly Eularian and Hamiltonian, (In fact, any C_n is Eularian and Hamiltonian.) Circular Permutations: The number of ways to arrange n distinct objects along a fixed circle is (n-1)! If there exists a walk in the connected graph that visits every vertex of the graph exactly once (except starting vertex) without repeating the edges and returns to the starting vertex, then such a walk is called as a Hamiltonian circuit. While this is a lot, it doesn’t seem unreasonably huge. In the mathematical field of graph theory, a Hamiltonian path (or traceable path) is a path in an undirected or directed graph that visits each vertex exactly once. 1 is 1-connected but its cube G3 = K4 -t- K3 is not Z -tough. It is also sometimes termed the tetrahedron graph or tetrahedral graph.. 1. Else if H is a graph as in case 3 we verify of e 3n – 6. Actualiy, (G 3) = 3; using Proposition 1.4, we conclude that t(G3y< 3. n t Fig. Toughness and harniltonian graphs It is easy to see that every cycle is 1-tough. The graph G in Fig. A Hamiltonian cycle (or Hamiltonian circuit) is a Hamiltonian path that is a cycle.Determining whether such paths and cycles exist in graphs is the Hamiltonian path problem, which is NP-complete. C4 (=K2,2) is a cycle of four vertices, 0 connected to 1 connected to 2 connected to 3 connected to 0. KW - IR-29721. First, in response to a conjecture of Chartrand, Kapoor and Nordhaus, a characterization of nonhamiltonian graphs isomorphic to their hamiltonian path graphs is presented. If e is not less than or equal to 3n – 6 then conclude that G is nonplanar. Dirac's Theorem - If G is a simple graph with n vertices, where n ≥ 3 If deg(v) ≥ {n}/{2} for each vertex v, then the graph G is Hamiltonian graph. Hamiltonian walk in graph G is a walk that passes through each vertex exactly once. A complete graph with 8 vertices would have = 5040 possible Hamiltonian circuits. The first three circuits are the same, except for what vertex Every hamiltonian graph is 1-tough. 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