VertexOutComponent

VertexOutComponent[g, {v1, v2, ...}] gives the vertices in the graph g that have a directed path from at least one of v1, v2, ....

• VertexOutComponent[g, {v1, v2, ...}, k] gives the vertices with a directed path from at least one of v1, v2, ... of at most length k.
• VertexOutComponent[g, {v1, v2, ...}, {k}] gives the vertices at length exactly k.
• VertexOutComponent[{v -> w, ...}, ...] uses rules v -> w to specify the graph g.

Examples

Find vertices reachable from a vertex:

g = Graph[{1 -> 2, 2 -> 3, 1 -> 4}];
VertexOutComponent[g, {1}]
(* {1, 2, 3, 4} *)

Limit search depth:

VertexOutComponent[g, {1}, 1]
(* {1, 2, 4} *)

Vertices at exact distance:

VertexOutComponent[g, {1}, {2}]
(* {3} *)

Please visit the official Wolfram Language Reference for more details.