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Spanning Trees with 1/2 the edges in a Eulerian Graph

I was attempting the following problem: Let $G$ be a connected simple graph. (a) If $G$ is eulerian with an even number of vertices, then it has a spanning subgraph $G'$ such that every node $i$ has ...
Roh4n's user avatar
  • 11
0 votes
1 answer
40 views

counting Eulerian circuits on complete directed graph

I have a complete directed graph $G$ (including self-loops). How can I count the number of Eulerian circuits on $G$? For example, in the simple case of $n=2$, there are clearly 4 Eulerian circuits. ...
lrussell's user avatar
1 vote
1 answer
272 views

Prove that an undirected connected graph $G$ contains an Euler circuit by some properties of its fundamental cut-set matrix and connectivity.

Let $G$ be an undirected connected graph. $\forall v∈V(G)$, $G-v$ (remove the node and all of its relevant edges from the graph) is still a connected graph. Besides, the fundamental cut-set matrix $S$ ...
zhengyuansu's user avatar
0 votes
1 answer
35 views

Show that this graph is a tree

Suppose we have a directed multigraph (a graph with loops and parallel edges), with vertex set $V=\{v_1,v_2,\cdots,v_n\}$, such that $d^+(v_i)=d^-(v_i)$ for every $i=1,2,\cdots,n$, i.e. indegree of ...
QED's user avatar
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1 vote
1 answer
495 views

A vertex $v$ is extendible if and only if $G − v$ is a forest.

I need help understanding the solution to this problem. This problem has been answered here, however, my doubt is not addressed. Problem: Let $G$ be a connected Eulerian graph with at least $3$ ...
beta_me me_beta's user avatar
2 votes
2 answers
1k views

Find the number of degree 1 vertices in terms of n and d

Fix an integer $d>1$. Let $G$ be a tree with $n$ vertices, and every vertex can have either degree $1$ or $d$. Find the number of degree $1$ vertices in terms of $d$ and $n$. I've been working on ...
primms123's user avatar
  • 151
0 votes
1 answer
460 views

Tree & Euler, Hamilton paths [closed]

If a tree on n vertices (n>1) has 2 pendant vertices, does it have Euler path or Hamilton path?
Kim's user avatar
  • 451