Euler path vs euler circuit

Aug 23, 2019 · Euler’s Path = a-b-c-d-a-g-f-e-c-a. Euler’s Circuit Theorem. A connected graph ‘G’ is traversable if and only if the number of vertices with odd degree in G is exactly 2 or 0. A connected graph G can contain an Euler’s path, but not an Euler’s circuit, if it has exactly two vertices with an odd degree. Note − This Euler path ...

Euler path vs euler circuit. An Euler circuit is a circuit that uses every edge in a graph with no repeats. Being a circuit, it must start and end at the same vertex. Example. The graph below has several possible Euler circuits. Here’s a couple, starting and ending at vertex A: ADEACEFCBA and AECABCFEDA. The second is shown in arrows.

An Euler Path is a way that goes through each edge of a chart precisely once. An Euler Circuit is an Euler Path that starts and finishes at a similar vertex. Conclusion. In this article, we learned that the Eulerian Path is a way in a diagram that visits each edge precisely once. Eulerian Circuit is an Eulerian Path that beginnings and closures ...

An Eulerian graph is a graph that possesses an Eulerian circuit. Example 9.4.1 9.4. 1: An Eulerian Graph. Without tracing any paths, we can be sure that the graph below has an Eulerian circuit because all vertices have an even degree. This follows from the following theorem. Figure 9.4.3 9.4. 3: An Eulerian graph.An Euler circuit is a way of traversing a graph so that the starting and ending points are on the same vertex. The most salient difference in distinguishing an Euler path vs. a circuit is that a ...👉Subscribe to our new channel:https://www.youtube.com/@varunainashots Any connected graph is called as an Euler Graph if and only if all its vertices are of...Finding a Hamiltonian Circuit • Nothing to do but enumerate all paths and see if any are Hamiltonian. • How many paths? Draw example from box graph. • Can think of all paths as a tree. Branching factor approximated by average degree d. Then dN leaves (paths). Exponential. Recall exponential curves from first lecture. Shortest vs. Longest PathTo test a household electrical circuit for short circuits or places where the circuit deviates from its path, use a multimeter. Set the multimeter to measure resistance, and test any electrical outlets that are suspected of having short cir...Many students are taught about genome assembly using the dichotomy between the complexity of finding Eulerian and Hamiltonian cycles (easy versus hard, respectively). This dichotomy is sometimes used to motivate the use of de Bruijn graphs in practice. In this paper, we explain that while de Bruijn graphs have indeed been very useful, the reason has nothing to do with the complexity of the ...When a short circuit occurs, electrical current experiences little to no resistance because its path has been diverted from its normal direction of flow. This in turn produces excess heat and can damage or destroy an electrical appliance.Oct 13, 2018 · A path which is followed to visitEuler Circuit is called Euler Path. That means a Euler Path visiting all edges. The green and red path in the above image is a Hamilton Path starting from lrft-bottom or right-top. Difference Between Hamilton Circuit and Euler Circuit

An Eulerian trail (or Eulerian path) is a path that visits every edge in a graph exactly once. An Eulerian circuit (or Eulerian cycle) is an Eulerian trail that starts and ends on the same vertex. A directed graph has an Eulerian cycle if and only if. Every vertex has equal in-degree and out-degree, and. All of its vertices with a non-zero ...Euler path = BCDBAD. Example 2: In the following image, we have a graph with 6 nodes. Now we have to determine whether this graph contains an Euler path. Solution: The above graph will contain the Euler path if each edge of this graph must be visited exactly once, and the vertex of this can be repeated.9. Euler Path || Euler Circuit || Examples of Euler path and Euler circuit #Eulerpath #EulercircuitRadhe RadheIn this vedio, you will learn the concept of Eu...Section 5. Euler’s Theorems. Recall: an Euler path or Euler circuit is a path or circuit that travels through every edge of a graph once and only once. The difference between a path and a circuit is that a circuit starts and ends at the same vertex, a path doesn't. Suppose we have an Euler path or circuit which starts at a vertex S Hamilton Path Hamilton Circuit *notice that not all edges need to be used *Unlike Euler Paths and Circuits, there is no trick to tell if a graph has a Hamilton Path or Circuit. A Complete Graph is a graph where every pair of vertices is joined by an edge. The number of Hamilton circuits in a complete graph with n vertices, including reversals ... An Eulerian circuit is an Eulerian path which begins and ends at the same vertex. A Hamiltonian path in {eq}G {/eq} is a path which traverses all the vertices of {eq}G {/eq}: that is, a path {eq}v_1 \to v_2 \to \dots \to v_n {/eq} where each vertex of {eq}G {/eq} occurs exactly once. Euler's sum of degrees theorem is used to determine if a graph has an Euler circuit, an Euler path, or neither. For both Euler circuits and Euler paths, the "trip" has to be completed "in one piece."

3-June-02 CSE 373 - Data Structures - 24 - Paths and Circuits 8 Euler paths and circuits • An Euler circuit in a graph G is a circuit containing every edge of G once and only once › circuit - starts and ends at the same vertex • An Euler path is a path that contains every edge of G once and only once › may or may not be a circuitAn Eulerian graph is a graph that possesses an Eulerian circuit. Example 9.4.1 9.4. 1: An Eulerian Graph. Without tracing any paths, we can be sure that the graph below has an Eulerian circuit because all vertices have an even degree. This follows from the following theorem. Figure 9.4.3 9.4. 3: An Eulerian graph.Euler Path For a graph to be an Euler Path, it has to have only 2 odd vertices. You will start and stop on different odd nodes. Vertex Degree Even/Odd A C Summary Euler Circuit: If a graph has any odd vertices, then it cannot have an Euler Circuit. If a graph has all even vertices, then it has at least one Euler Circuit (usually more). Euler Path: Euler path and circuit. An Euler path is a path that uses every edge of the graph exactly once. Edges cannot be repeated. This is not same as the complete graph as it needs to be a path that is an Euler path must be traversed linearly without recursion/ pending paths. This is an important concept in Graph theory that appears frequently in real ...Feb 6, 2023 · Following are some interesting properties of undirected graphs with an Eulerian path and cycle. We can use these properties to find whether a graph is Eulerian or not. Eulerian Cycle: An undirected graph has Eulerian cycle if following two conditions are true. All vertices with non-zero degree are connected.

Langston hughes interesting facts.

Apr 10, 2018 · If a graph has a Eulerian circuit, then that circuit also happens to be a path (which might be, but does not have to be closed). – dtldarek. Apr 10, 2018 at 13:08. If "path" is defined in such a way that a circuit can't be a path, then OP is correct, a graph with an Eulerian circuit doesn't have an Eulerian path. – Gerry Myerson. So Euler's Formula says that e to the jx equals cosine X plus j times sine x. Sal has a really nice video where he actually proves that this is true. And he does it by taking the MacLaurin …What are the Eulerian Path and Eulerian Cycle? According to Wikipedia, Eulerian Path (also called Eulerian Trail) is a path in a finite graph that visits every edge exactly once.The path may be ...Example In the graph shown below, there are several Euler paths. One such path is CABDCB. The path is shown in arrows to the right, with the order of edges numbered. Euler Circuit An Euler circuit is a circuit that uses every edge in a graph with no repeats. Being a circuit, it must start and end at the same vertex. Example

1. An Euler path is a path that uses every edge of a graph exactly once.and it must have exactly two odd vertices.the path starts and ends at different vertex. A Hamiltonian cycle is a cycle that contains every vertex of the graph hence you may not use all the edges of the graph. Share. Follow.An Euler path (or Eulerian path) in a graph \(G\) is a simple path that contains every edge of \(G\). The same as an Euler circuit, but we don't have to end up back at the beginning. The other graph above does have an Euler path. Theorem: A graph with an Eulerian circuit must be connected, and each vertex has even degree.Section 5. Euler's Theorems. Recall: an Euler path or Euler circuit is a path or circuit that travels through every edge of a graph once and only once. The difference between a path and a circuit is that a circuit starts and ends at the same vertex, a path doesn't. Suppose we have an Euler path or circuit which starts at a vertex SThanks to all of you who support me on Patreon. You da real mvps! $1 per month helps!! :) https://www.patreon.com/patrickjmt !! Euler Circuits and Euler P...Vertex Edge, Hamilton Path and Euler Path resources. Quiz and great student activity for Euler Paths, as well as extra practice for Hamilton and Vertex Edge ...Jul 18, 2022 · Figure 6.3.1 6.3. 1: Euler Path Example. One Euler path for the above graph is F, A, B, C, F, E, C, D, E as shown below. Figure 6.3.2 6.3. 2: Euler Path. This Euler path travels every edge once and only once and starts and ends at different vertices. This graph cannot have an Euler circuit since no Euler path can start and end at the same ... Euler Paths and Circuits Corollary : A connected graph G has an Euler path, but no Euler circuits Ù exactly two vertices of G has odd degree. W }}(W dZ ^}voÇ](_ dZ P }( Z starting and ending vertices of the Euler path must be odd, and all the others must be even. dZ ^](_ > µv À Z À ] Á] Z odd degrees.To check if your undirected graph has a Eulerian circuit with an adjacency list representation of the graph, count the number of vertices with odd degree. This is where you can utilize your adjacency list. If the odd count is 0, then check if all the non-zero vertices are connected. You can do this by using DFS traversals.1. The question, which made its way to Euler, was whether it was possible to take a walk and cross over each bridge exactly once; Euler showed that it is not possible. Figure 5.2.1 5.2. 1: The Seven Bridges of Königsberg. We can represent this problem as a graph, as in Figure 5.2.2 5.2.$\begingroup$ For (3), it is known that a graph has an eulerian cycle if and only if all the nodes have an even degree. That's linear on the number of nodes. $\endgroup$ – frabala

Lemma 1: If G is Eulerian, then every node in G has even degree. Proof: Let G = (V, E) be an Eulerian graph and let C be an Eulerian circuit in G. Fix any node v. If we trace through circuit C, we will enter v the same number of times that we leave it. This means that the number of edges incident to v that are a part of C is even. Since C

Graph (a) has an Euler circuit, graph (b) has an Euler path but not an Euler circuit and graph (c) has neither a circuit nor a path. (a) (b) (c) Figure 2: A graph containing an Euler circuit (a), one containing an Euler path (b) and a non-Eulerian graph (c) 1.4. Finding an Euler path There are several ways to find an Euler path in a given graph.Mathematical Models of Euler's Circuits & Euler's Paths 6:54 Euler's Theorems: Circuit, Path & Sum of Degrees 4:44 Fleury's Algorithm for Finding an Euler Circuit 5:20This lesson explains Euler paths and Euler circuits. Several examples are provided. Site: http://mathispower4u.comA specific circuit-remover matrix O =11T−I O = 1 1 T − I, Where 1 1 is the column vector of N N ones. ( O O is basically a logically inverted unit matrix, 0 0 on diagonal and 1 1 everywhere else) Now define the matrix : {T0 =MTk+1 =M(O ⊗ Tk) { T 0 = M T k + 1 = M ( O ⊗ T k) Then calculate the sum.An Eulerian cycle, also called an Eulerian circuit, Euler circuit, Eulerian tour, or Euler tour, is a trail which starts and ends at the same graph vertex. In other words, it is a graph cycle which uses each graph edge exactly once. For technical reasons, Eulerian cycles are mathematically easier to study than are Hamiltonian cycles. An …Figure 6.5.3. 1: Euler Path Example. One Euler path for the above graph is F, A, B, C, F, E, C, D, E as shown below. Figure 6.5.3. 2: Euler Path. This Euler path travels every edge once and only once and starts and ends at different vertices. This graph cannot have an Euler circuit since no Euler path can start and end at the same vertex ...The definition says "A directed graph has an eulerian path if and only if it is connected and each vertex except 2 have the same in-degree as out-degree, and one of those 2 vertices has out-degree with one greater than in-degree (this is the start vertex), and the other vertex has in-degree with one greater than out-degree (this is the end vertex)."The difference between an Euler path and an. Euler circuit is that an Euler circuit must start and end at the same vertex. Page 17. Examples. Euler path.Focusing on the case for the Eulerian path (the cycle case can be solved by removing one edge and treating it as an Eulerian path problem), ... Abiguity being referred to in the algorithm of finding an Euler Circuit from a graph having all vertices of even degree. Hot Network Questions

Samsung tu8000 review.

Battery control module 2015 chevy malibu.

An Euler path (or Eulerian path) in a graph \(G\) is a simple path that contains every edge of \(G\). The same as an Euler circuit, but we don't have to end up back at the beginning. The other graph above does have an Euler path. Theorem: A graph with an Eulerian circuit must be connected, and each vertex has even degree.A path which is followed to visitEuler Circuit is called Euler Path. That means a Euler Path visiting all edges. The green and red path in the above image is a Hamilton Path starting from lrft-bottom or right-top. Difference Between Hamilton Circuit and Euler CircuitWhen a short circuit occurs, electrical current experiences little to no resistance because its path has been diverted from its normal direction of flow. This in turn produces excess heat and can damage or destroy an electrical appliance.Defitition of an euler graph "An Euler circuit is a circuit that uses every edge of a graph exactly once. An Euler path starts and ends at different vertices. An Euler circuit starts and ends at the same vertex." According to my little knowledge "An eluler graph should be degree of all vertices is even, and should be connected graph".Recall that a graph has an Eulerian path (not circuit) if and only if it has exactly two vertices with odd degree. Thus the existence of such Eulerian path proves G f egis still connected so there are no cut edges. Problem 3. (20 pts) For each of the three graphs in Figure 1, determine whether they have an Euler walk and/or an Euler circuit. I've got this code in Python. The user writes graph's adjency list and gets the information if the graph has an euler circuit, euler path or isn't eulerian.Euler paths are an optimal path through a graph. They are named after him because it was Euler who first defined them. By counting the number of vertices of a graph, and their degree we can determine whether a graph has an Euler path or circuit. We will also learn another algorithm that will allow us to find an Euler circuit once we determine ...An Eulerian circuit is an Eulerian path which begins and ends at the same vertex. A Hamiltonian path in {eq}G {/eq} is a path which traverses all the vertices of {eq}G {/eq}: that is, a path {eq}v_1 \to v_2 \to \dots \to v_n {/eq} where each vertex of {eq}G {/eq} occurs exactly once. Apr 15, 2022 · Euler's Path Theorem. This next theorem is very similar. Euler's path theorem states the following: 'If a graph has exactly two vertices of odd degree, then it has an Euler path that starts and ... A path which is followed to visitEuler Circuit is called Euler Path. That means a Euler Path visiting all edges. The green and red path in the above image is a Hamilton Path starting from lrft-bottom or right-top. Difference Between Hamilton Circuit and Euler CircuitTroubleshooting air conditioner equipment that caused tripped circuit breaker. Expert Advice On Improving Your Home Videos Latest View All Guides Latest View All Radio Show Latest View All Podcast Episodes Latest View All We recommend the b...👉Subscribe to our new channel:https://www.youtube.com/@varunainashots Any connected graph is called as an Euler Graph if and only if all its vertices are of... ….

An Euler circuit in a graph without isolated nodes is a circuit that contains every edge exactly one. Definition. An Hamiltonian circuit in a graph is a circuit ...On the other hand, there is a concept named Eulerian Circuits (or Eulerian Cycle) that restricts Eulerian Path conditions further. It is still an Eulerian Path and it starts and ends at the same ...Graph (a) has an Euler circuit, graph (b) has an Euler path but not an Euler circuit and graph (c) has neither a circuit nor a path. (a) (b) (c) Figure 2: A graph containing an Euler circuit (a), one containing an Euler path (b) and a non-Eulerian graph (c) 1.4. Finding an Euler path There are several ways to find an Euler path in a given graph.1. An Euler path is a path that uses every edge of a graph exactly once.and it must have exactly two odd vertices.the path starts and ends at different vertex. A Hamiltonian cycle is a cycle that contains every vertex of the graph hence you may not use all the edges of the graph. Share. Follow.0. By definition a path graph cannot have an Eulerian circuit or a Hamiltonian cycle. A loop graph (consisting of one edge and one vertex) has both an Eulerian circuit and a Hamiltonian cycle. As above, there are examples where a graph might have one but not the other. The answer to your question is that there is no …Euler Path. An Euler path is a path that uses every edge in a graph with no repeats. Being a path, it does not have to return to the starting vertex. Example. In the graph shown below, there are several Euler paths. One such path is CABDCB. The path is shown in arrows to the right, with the order of edges numbered. nd one. When searching for an Euler path, you must start on one of the nodes of odd degree and end on the other. Here is an Euler path: d !e !f !c !a !b !g 4.Before searching for an Euler circuit, let’s use Euler’s rst theorem to decide if one exists. According to Euler’s rst theorem, there is an Euler circuit if and only if all nodes have9. Euler Path || Euler Circuit || Examples of Euler path and Euler circuit #Eulerpath #EulercircuitRadhe RadheIn this vedio, you will learn the concept of Eu... Euler path vs euler circuit, nd one. When searching for an Euler path, you must start on one of the nodes of odd degree and end on the other. Here is an Euler path: d !e !f !c !a !b !g 4.Before searching for an Euler circuit, let’s use Euler’s rst theorem to decide if one exists. According to Euler’s rst theorem, there is an Euler circuit if and only if all nodes have, I had some mistakes during the second half of this video and interchanged some of the terms such as vertex, degree and etc. Maybe because of nervousness and ..., Eulerian Circuit: Visits each edge exactly once. Starts and ends on same vertex. Is it possible a graph has a hamiltonian circuit but not an eulerian circuit? Here is my attempt based on proof by contradiction: Suppose there is a graph G that has a hamiltonian circuit. That means every vertex has at least one neighboring edge. <-- stuck, Definition. An Eulerian trail, [3] or Euler walk, in an undirected graph is a walk that uses each edge exactly once. If such a walk exists, the graph is called traversable or semi …, A connected graph has an Eulerian path if and only if etc., etc. - Gerry Myerson. Apr 10, 2018 at 11:07. @GerryMyerson That is not correct: if you delete any edge from a circuit, the resulting path cannot be Eulerian (it does not traverse all the edges). If a graph has a Eulerian circuit, then that circuit also happens to be a path (which ..., Not only is there a path between vertices a and g, but vertex g bridges the gap between a and c with the path a → b → g → c. Similarly, there is a path between vertices a and d and vertices a and f: a → b → g → d, a …, Determine whether there is Euler circuit. The exercise: Asks for both of Eulerian circuit and path circuit. Conditions: 1)-Should stop at the same point that started from. 2)- Don't repeat edges. 3)-Should cross all edges. After long time of focusing I found the Eulerian path, I tried so much on the circuit but could not find it., An Euler Path is a path that goes through every edge of a graph exactly once An Euler Circuit is an Euler Path that begins and ends at the same vertex. Euler Path Euler Circuit Euler’s Theorem: 1. If a graph has more than 2 vertices of odd degree then it has no Euler paths. 2. If a graph is connected and has 0 or exactly 2 vertices of odd ... , Euler Paths and Circuits I Theorem: A graph has an Euler path but not an Euler circuit i it has exactly two vertices of odd edge. I Proof: [The "only if" case]-The degree of the start and end vertices of the Euler path must be odd.-All the others must be even. I Proof: [The "if" case]-Let u and v be the vertices with odd degrees., Lemma 1: If G is Eulerian, then every node in G has even degree. Proof: Let G = (V, E) be an Eulerian graph and let C be an Eulerian circuit in G. Fix any node v. If we trace through circuit C, we will enter v the same number of times that we leave it. This means that the number of edges incident to v that are a part of C is even. Since C , Rosen, published by McGraw Hill, Boston, MA, 2006. Euler Paths and Circuits ... An Euler circuit is an Euler path that returns to its start. A. B. C. D. Does this ..., An Eulerian circuit is an Eulerian path which begins and ends at the same vertex. A Hamiltonian path in {eq}G {/eq} is a path which traverses all the vertices of {eq}G {/eq}: that is, a path {eq}v_1 \to v_2 \to \dots \to v_n {/eq} where each vertex of {eq}G {/eq} occurs exactly once. A Hamiltonian circuit is a closed Hamiltonian path: that is ..., 1. The question, which made its way to Euler, was whether it was possible to take a walk and cross over each bridge exactly once; Euler showed that it is not possible. Figure 5.2.1 5.2. 1: The Seven Bridges of Königsberg. We can represent this problem as a graph, as in Figure 5.2.2 5.2., 4 de jul. de 2018 ... Euler path & Euler circuit. An Euler path is a path that uses every edge of a graph exactly once. An Euler circuit is a circuit that uses ..., The most salient difference in distinguishing an Euler path vs. a circuit is that a path ends at a different vertex than it started at, while a circuit stops where it starts. An..., The Euler circuit for this graph with the new edge removed is an Euler trail for the original graph. The corresponding result for directed multigraphs is Theorem 3.2 A connected directed multigraph has a Euler circuit if, and only if, d+(x) = d−(x). It has an Euler trail if, and only if, there are exactly two vertices with d+(x) 6=, When it comes to electrical circuits, there are two basic varieties: series circuits and parallel circuits. The major difference between the two is the number of paths that the electrical current can flow through., What I did was I drew an Euler path, a path in a graph where each side is traversed exactly once. A graph with an Euler path in it is called semi-Eulerian. I thoroughly enjoyed the challenge and ..., Rather than finding a minimum spanning tree that visits every vertex of a graph, an Euler path or circuit can be used to find a way to visit every edge of a graph once and only once. This would be useful for …, Euler Paths. Each edge of Graph 'G' appears exactly once, and each vertex of 'G' appears at least once along an Euler's route. If a linked graph G includes an …, 3-June-02 CSE 373 - Data Structures - 24 - Paths and Circuits 8 Euler paths and circuits • An Euler circuit in a graph G is a circuit containing every edge of G once and only once › circuit - starts and ends at the same vertex • An Euler path is a path that contains every edge of G once and only once › may or may not be a circuit, This lesson explains Euler paths and Euler circuits. Several examples are provided. Site: http://mathispower4u.com, Jun 26, 2023 · Here 1->2->4->3->6->8->3->1 is a circuit. Circuit is a closed trail. These can have repeated vertices only. 4. Path – It is a trail in which neither vertices nor edges are repeated i.e. if we traverse a graph such that we do not repeat a vertex and nor we repeat an edge. As path is also a trail, thus it is also an open walk. , math 55 - eulerian paths April 23 An Euler path in a graph G is a simple path (no repeated edges) containing every edge of G. An Euler circuit is an Euler path beginning and ending at the same vertex. We have two theorems about when these exist: 1.A connected graph G with at least 2 vertices has an Euler circuit i each vertex has even degree., Start with an empty stack and an empty circuit (eulerian path). If all vertices have even degree: choose any of them. This will be the current vertex. If there are exactly 2 vertices having an odd degree: choose one of them. This will be the current vertex. Otherwise no Euler circuit or path exists., Construction of Euler Circuits Let G be an Eulerian graph. Fleury’s Algorithm 1.Choose any vertex of G to start. 2.From that vertex pick an edge of G to traverse. Do not pick a bridge unless there is no other choice. 3.Darken that edge as a reminder that you cannot traverse it again. 4.Travel that edge to the next vertex., Teahouse accommodation is available along the whole route, and with a compulsory guide, anybody with the correct permits can complete the circuit. STRADDLED BETWEEN THE ANNAPURNA MOUNTAINS and the Langtang Valley lies the comparatively undi..., A Euler circuit by definition visits each edge exactly once. I don't understand what you mean by "minimizing the number of times the edge appears in the solution"; if you're trying to construct a Euler circuit, by definition this number is minimized., What's the difference between a euler trail, path,circuit,cycle and a regular trail,path,circuit,cycle since edges cannot repeat for all of them anyway? And can vertices be repeated in a euler path? Clarification will be much appreciated.Thanks. discrete-mathematics graph-theory Share Cite Follow edited Jul 20, 2017 at 13:44, An Euler Path is a path that goes through every edge of a graph exactly once An Euler Circuit is an Euler Path that begins and ends at the same vertex. Euler Path Euler Circuit Euler’s Theorem: 1. If a graph has more than 2 vertices of odd degree then it has no Euler paths. 2. If a graph is connected and has 0 or exactly 2 vertices of odd ..., An Euler path (or Eulerian path) in a graph \(G\) is a simple path that contains every edge of \(G\). The same as an Euler circuit, but we don't have to end up back at the beginning. The other graph above does have an Euler path. Theorem: A graph with an Eulerian circuit must be connected, and each vertex has even degree., Aug 23, 2019 · Euler’s Path = a-b-c-d-a-g-f-e-c-a. Euler’s Circuit Theorem. A connected graph ‘G’ is traversable if and only if the number of vertices with odd degree in G is exactly 2 or 0. A connected graph G can contain an Euler’s path, but not an Euler’s circuit, if it has exactly two vertices with an odd degree. Note − This Euler path ... , Eulerian Path: An undirected graph has Eulerian Path if following two conditions are true. Same as condition (a) for Eulerian Cycle. If zero or two vertices have odd degree and all other vertices have even degree. Note that only one vertex with odd degree is not possible in an undirected graph (sum of all degrees is always even in an undirected ...