Path Finding algorithm?

[prograComp]

Can anybody tell me which is the best path finding algorithm if the path contains loops?

[StTwister]

Any path finding algorithm works with loops EXCEPT the situation where there are negative-cost loops, when a minimum cost path is not possible.

[msg555]

If a shortest path inlcudes a loop (I'm assuming we are in fact talking about shortest paths) then that loop must be a negative cycle. The Bellman Ford algorithm can detect negative cycles while computing shortest paths. http://en.wikipedia.org/wiki/Bellman-Ford_algorithm