This crate provides data structures to model graphs and to perform algorithms on these data structures. The functionality presented is designed to be easy to use, flexible, and performant.

Currently supported are:

Undirected graph types Graph and AppendGraph, built on a flat, index-based adjacency list,
Maps to freely associate custom data with vertices and edges,
Connectivity and pathing algorithms: Dijkstra's algorithm, DFS, and BFS in different variants,
Exposed traits to implement custom graph data structures or algorithms.

For more information, see the documentation.

Example

// Brings commonly used traits into scope.
use grapherity::prelude::*;
use grapherity::models::Graph;
use grapherity::algorithms;

let mut graph = Graph::new();
// Creates a map for edge weights with a default weight.
let mut weights = graph.edge_map(1);
// Adds three vertices and two edges.
let v1 = graph.add_vertex();
let v2 = graph.add_vertex();
let v3 = graph.add_vertex();
graph.add_edge(v1, v2);
let e = graph.add_edge(v2, v3);
// Sets a non-default weight for the second edge.
weights[e] = 5;

// Checks the number of vertices.
assert_eq!(graph.vertex_count(), 3);
// Checks the number of edges.
assert_eq!(graph.edge_count(), 2);
// Checks that v1 and v2 are adjacent.
assert!(graph.are_adjacent(v1, v2));
// Checks that v1 and v3 are not adjacent.
assert!(!graph.are_adjacent(v1, v3));
// Checks the sum of all vertex degrees.
let sum: usize = graph.vertices().map(|v| graph.degree(v)).sum();
assert_eq!(sum, 1 + 2 + 1);

// Calls Dijkstra's algorithm using the edge weights to find the shortest path from v1 to v3.
let result = algorithms::dijkstra(&graph, v1, |e| weights[e]);
assert_eq!(result.distances[v3], Some(1 + 5));
assert_eq!(result.predecessors[v3], Some(v2));

// Deletes the middle vertex and its incident edges.
graph.delete_vertex(v2);

// Calls Dijkstra's algorithm again on the now disconnected graph.
let result = algorithms::dijkstra(&graph, v1, |e| weights[e]);
assert_eq!(result.distances[v3], None);
assert_eq!(result.predecessors[v3], None);

License

This project is dual-licensed under the terms of both:

Apache License, Version 2.0, (LICENSE-APACHE or https://www.apache.org/licenses/LICENSE-2.0)
MIT license (LICENSE-MIT or https://opensource.org/license/mit)

You may choose either license for your use of this software.

Contributions

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you, as defined in the Apache-2.0 license, shall be dual licensed as above, without any additional terms or conditions.