Add generators::path, without tests

src/generators.rs

@@ -44,6 +44,23 @@ where
     )
 }
 
+/// Generates a path graph.
+///
+/// Generates a path with `n` edges in `graph` as a new connected component and returns the new
+/// vertices *v0, v1, ..., vn* and edges *e0, e1, ..., e(n - 1)* in order, i.e. *e0 = (v0, v1)*,
+/// *e1 = (v1, v2)*, etc.
+///
+/// For `n == 0`, only a single vertex and no edges are added.
+pub fn path<G: GraphTopologyAddition>(graph: &mut G, n: usize) -> (Vec<G::Vertex>, Vec<G::Edge>) {
+    graph.reserve_vertices(n + 1);
+    graph.reserve_edges(n);
+    let vertices: Vec<_> = (0..n + 1).map(|_| graph.add_vertex()).collect();
+    let edges = (0..n)
+        .map(|i| graph.add_edge(vertices[i], vertices[i + 1]))
+        .collect();
+    (vertices, edges)
+}
+
 /// Generates a Petersen graph.
 ///
 /// Generates a [Petersen graph] in `graph` as a new connected component and returns the new