[GAP Forum] shortest paths from s to every vertex of G

[Nicoleta Gramisteanu]

Can you tell me how can i make more efficient this problems? 
We have a directed graph and a function of weight w  we know that there is only one edge with a negative weight and that there is no cycle in the graph with negative weight   we have s a vertex
We have to find an algorithm that find the length of all the shortest paths  from s to every vertex of G