Questions tagged [hamiltonian-path]

Questions on Hamiltonian paths, that is, paths that visit each vertex exactly once in a graph.

95 questions
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How can the shortest traveling salesman tour be found in $O(2^n poly(n))$ time and less than exponential space?

I'm stuck on problem 9.4 from The Nature of Computation which reads: Dynamic Salesman. A naive search algorithm for TSP takes $O(n!)$ time to check all tours. Use dynamic programming to reduce this to a simple exponential, i.e., to solve TSP in…
8
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3 answers

Constructing a random Hamiltonian Cycle (Secret Santa)

I was programming a little Secret Santa tool for my extended family's gift exchange. We had a few constraints: No recipients within the immediate family Nobody should get who they got last year The whole thing should be a cycle (Sandy gives to…
7
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What TSP variant doesn't return to start point?

For my case I have starting point and several cities. I want the shortest route to visit all cities without returning starting point. I have read several TSP algorithm and all include the return a full cycle. So what TSP variation should I look for…
6
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Upper bound on the number of hamiltonian cycles on a $n \times n $ grid graph

What is the best upper bound that is known for the number of hamiltonian cycles on a $n \times n $ grid graph? I did some searching and found that the number of hamiltonian cycles on a planar graph with $n$ vertices is $O(\sqrt[4]{30}^n)$ where $n$…
6
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2 answers

Greedy and backtracking solutions to an arrangement problem with constraints

I'm revising for my finals. I have found a pattern in past papers in terms of a recurring question, reworded coming up every year. But I've no idea what the marker actually wants... I've asked class mates but they all seemed to be confused. One gave…
6
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3 answers

Proof that Hamiltonian cycle/circuit with a specified edge is NP-complete

I'm a little stuck on this question, any help would be appreciated! Given that the Hamiltonian Path (HP) and the Hamiltonian Circuit/Cycles (HC) problems are known to be NP-complete, show that HCE is NP-complete. HCE: Given an undirected graph G and…
Lawliet
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Find a simple path visiting all marked vertices

Let $G = (V, E)$ be a connected graph and let $M\subseteq V$. We say that a vertex $v$ is marked if $v\in M$. The problem is to find a simple path in $G$ that visits the maximum possible number of marked vertices. The associated decision problem…
5
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3 answers

Rearranging strings so that the Hamming distance between them is 1

This is a question from CodeFights.com: Given an array of equal-length strings, check if it is possible to rearrange the strings in such a way that after the rearrangement the strings at consecutive positions would differ by exactly one…
5
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3 answers

How to generate graphs with a Hamiltonian path?

I need to create a graph generator for my next project. Generally algorithms are trying to find a Hamiltonian path in a graph. So I can create a graph generator, generate a graph, and then I can decide whether the graph has a Hamiltonian path or…
5
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3 answers

Find hamilton cycle in a directed graph reduced to sat problem

I need to find a Hamiltonian cycle in a directed graph using propositional logic, and to solve it by sat solver. So after I couldn't find a working solution, I found a paper that describes how to construct a CNF formula to find an Hamiltonian…
5
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Does the Bondy-Chvátal theorem have algorithmic applications beyond Ore's theorem?

I'm toying around with graph properties and I want to make some effort to check whether a given graph is Hamiltonian. I understand that the general problem is NP-complete, but I'm looking for simple checks that are easy to implement and…
Fasermaler
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Hamiltonian circuit for a family of graphs

For $\Sigma = \{a,b\}$, let $S_n = \{w\mid w \in \Sigma^{*} \land |w| = n\}$. Let $C_n \subset \Sigma^{*}$ be the language of circular strings that contain as substrings all elements of $S_n$. For instance, $bbaaaababaabbbba \in C_4$ I have…
5
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1 answer

Easy infinite subclass of cubic graphs for Hamiltonian cycle problem

I know that Hamiltonian cycle problem is $NP$-complete for 2-connected planar bipartite cubic graphs. I'm interested in non-trivial infinite subclass of cubic graphs where the Hamiltonian cycle (path) problem is efficiently solvable. I tried the…
Mohammad Al-Turkistany
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Is Hamiltonian path NP-hard on graphs of diameter 2?

Let $G$ be a graph of diameter 2 ($\forall u,v\in V: d(u,v)\leq2$). Can we decide if $G$ has Hamiltonian path in poly time? What about digraphs? Perhaps some motivation is in place: the question arises from Dirac's theorem which states that if…
R B
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Why is Adleman's molecular algorithm for Hamiltonian Path linear?

In Adleman's 1994 paper (archived), he describes a method of manipulating DNA molecules in a lab that results in a solution to the Hamiltonian Path problem with high probability. He claims that "The number of different oligonucleotides required…
idoby
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