A loop is an edge that starts and ends at the same node and passes through no other nodes.
IsLoopFree(arcSources, arcTargets, numNodes)
TRUE if the graph is loop free, FALSE otherwise
Vector corresponding to the source nodes of a graph's edges
Vector corresponding to the destination nodes of a graph's edges
The number of nodes in the graph
See https://lemon.cs.elte.hu/pub/doc/1.3.1/a00616.html#ga127f3963003cd532c79c226885fe1c8c for more information.