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1 vote
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15-game graph contains a Hamiltonian path ? Lovász conjecture for groupoids, loops, quasigroups , etc?

Typically Cayley graphs are defined for groups and generators sets S. But basically one only needs some set S and another set V and partially defined operation SxV->V, then one defines graph with ...
Alexander Chervov's user avatar
2 votes
0 answers
112 views

Constructing Hamiltonian circuits in acyclic digraphs

Any directed graph $G$ lacking cycles can acquire a Hamiltonian circuit through the addition of a sufficient number of edges. Q. Is there a method to minimize the addition of edges to achieve a ...
ABB's user avatar
  • 4,058
2 votes
1 answer
177 views

Inspired by a card game: finding a path through $[\mathbb{N}]^n$

Motivation. Today my sons played a card game, in which a fixed number $n$ of cards was lying on the table. A move consists of adding an unused card to the cards on the table, and removing a card from ...
Dominic van der Zypen's user avatar
9 votes
2 answers
2k views

Is this graph Hamiltonian?

Let $G$ be a simple $2$-connected graph with $m+n$ vertices ($n>m \geq 3$) with degree sequence $(m-1)^m$, $(n-1)^n$; that is, $G$ is degree-equivalent to two disjoint cliques $K_m$, $K_n$ of ...
Valentin Brimkov's user avatar
0 votes
1 answer
115 views

Sources of information on algorithms for finding Hamiltonian cycles (Pósa)

I research various algorithms in complex networks and I am quite new in this field. I am currently focusing on random geometric graphs - Pósa's algorithm for finding a hamiltonian cycle. Can you ...
Ido314's user avatar
  • 1
9 votes
2 answers
2k views

"Gray code" of all permutations

Informally asking, can we step through all permutations of the set $\{1,\ldots,n\}$ by just using transpositions? More formally: For any $n\in\mathbb{N}$ let $[n] = \{1,\ldots,n\}$ and let $S_n$ be ...
Dominic van der Zypen's user avatar
1 vote
1 answer
78 views

Graph gadget related to uniquely hamiltionian regular graphs (question #2)

Related to uniquely hamiltionian graphs. For natural numbers $a,b$ define $(a,b)$ gadget $G$: $G$ is finite simple graph. Two vertices $u,v$ are of degree $b$ and the rest of the vertices are of ...
joro's user avatar
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5 votes
0 answers
99 views

Graph gadget related to uniquely hamiltionian regular graphs

A graph is uniquely hamiltonian if it has exactly one hamiltonian cycle. According to a conjecture there are no $r$-regular uniquely hamiltonian graphs for $r > 2$ and of special interest is the ...
joro's user avatar
  • 25.4k