I think that if the graph is like this ==>
v1 --> v2 --> v3 --> v4 --> v5 --> v6 --> ... v100 and all the edge weights are equal to 1.
so, i think graph is topologically sorted by bellman ford and so now we process the edges
in order (v1,v2) (v2,v3) (v3,v4) (v4,v5) (v5,v6) as the edges in the path in one more than the preceding one.
so, we can find distance from source to any vertex by path relaxation property of bellman ford ....