The main issue is that the hamiltonian path method calls the longest path 
method.

We should provide a dedicated ILP for hamiltonian path that could 
optionally search for a hamiltonian path of minimum/maximum cost. 


Le mardi 6 février 2018 19:39:32 UTC+1, Dima Pasechnik a écrit :
>
>
>
> On Tuesday, February 6, 2018 at 5:18:02 PM UTC, Avinandan Das wrote:
>>
>> Consider the following :-
>>
>> a=[[0, 4, 8], [9, 0, 9], [1000, 1000, 0]]
>> a=Matrix(a)
>>  H=DiGraph(a,weighted=True)
>>  H.hamiltonian_path(used_edge_labels=True)
>>
>> This returns (1009, Subgraph of (): Digraph on 3 vertices) but the 
>> minimum weight Hamiltonian path has weight 13.
>>
>
> Looking at the source code, it seems that it actually returns maximum  
> weight Hamiltonian path.
>
> https://github.com/sagemath/sage/blob/07d6c37d18811e2b377a9689790a7c5e24da16ba/src/sage/graphs/generic_graph.py#L7137
>
>
>
>
>
> I suppose we should amend the documentation.
>
>>
>> I have installed sage-8.1 and my operating system is Ubuntu 14.04 LTS (64 
>> bit) and my processor is Intel® Core™ i5-3210M CPU @ 2.50GHz × 4 .
>>
>

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