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7 votes
7 answers
3k views

Efficient Hamiltonian cycle algorithms for graph classes

Generally speaking, finding a Hamiltonian cycle is NP-Hard and so tough. But if $G=L(H)$ is the line graph of $H$, then we can reduce the problem of finding a Hamiltonian cycle in $G$ to finding an ...
Felix Goldberg's user avatar
4 votes
1 answer
2k views

How many edge-disjoint cycles of length 3 are in the complete graph?

A couple of questions related to edge-disjoint cycles. Let $K_n = (V,E)$ be the complete graph on $|V|=n$ nodes. Two cycles are 'edge disjoint' if they do not share any edges. What is the size of ...
dan's user avatar
  • 599
3 votes
1 answer
503 views

Compute number vertex disjoint cycles in graph surrounding a face

Hi all, If anyone has insight into the following variant of the classic problem of packing vertex-disjoint cycle into graphs I would be interested. Given a finite undirected graph $G$ embedded in $...
momeara's user avatar
  • 211
2 votes
3 answers
16k views

Cycle of length 4 in an undirected graph

Can anyone give me a hint for an algorithm to find a simple cycle of length 4 (4 edges and 4 vertices that is) in an undirected graph, given as an adjacency list? It needs to use $O(v^3)$ operations (...
user15816's user avatar
2 votes
4 answers
6k views

Counting simple 4-cycles in an undirected graph [closed]

I'm looking for an algorithm which just counts the number of simple and distinct 4-cycles in an undirected graph labelled with integer keys. I don't need it to be optimal because I only have to use it ...
Dree's user avatar
  • 121
2 votes
2 answers
553 views

Need input on a potentially NP-hard maximal edge-weighted multi-cycle graph

I've posted a question on Stack Overflow regarding a seemingly NP-hard problem on maximization of weighted cycles in a graph problem. One of the respondents cited Professor David Speyer's Math ...
Some Newbie's user avatar
2 votes
1 answer
82 views

Algorithms for heaviest edge-disjoint cycle collection contained in graph's set of edges

given a biconnected symmetric graph with weighted edges, what is the algorithmic complexity of determining a set of pairwise edge-disjoint cycles with maximal sum of edge weights if there are no other ...
Manfred Weis's user avatar
  • 13.2k
2 votes
0 answers
388 views

A fast algorithm for deciding if a given undirected graph contains a C4 subgraph

I'm looking for an algorithm for deciding if a given undirected graph G contains C4 as a sub graph, not necessarily induced. I'm not interested in finding such a cycle, if it exists. I was told there ...
Itai Pelles's user avatar