Function empty_graph 

pub fn empty_graph<Ty: EdgeType, Ix: IndexType>(
    n: usize,
) -> Graph<(), (), Ty, Ix>

Generates an empty graph with n nodes and no edges.

Examples

use petgraph::Graph;
use petgraph_gen::empty_graph;

let graph: Graph<(), ()> = empty_graph(5);
assert_eq!(graph.node_count(), 5);
assert_eq!(graph.edge_count(), 0);