https://github.com/mitchellh/zig-graph

Directed graph data structure for Zig
https://github.com/mitchellh/zig-graph

Last synced: 2 months ago
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Directed graph data structure for Zig

• Host: GitHub
• URL: https://github.com/mitchellh/zig-graph
• Owner: mitchellh
• License: mit
• Created: 2021-12-17T21:06:40.000Z (over 2 years ago)
• Default Branch: main
• Last Pushed: 2022-09-13T21:01:06.000Z (almost 2 years ago)
• Last Synced: 2024-04-16T00:05:56.536Z (2 months ago)
• Language: Zig
• Size: 38.1 KB
• Stars: 86
• Watchers: 4
• Forks: 5
• Open Issues: 0
• Metadata Files:
  • Readme: README.md
  • License: LICENSE

Lists

• awesome-zig - zig-graph🗒️Directed graph data structure for Zig
• awesome-zig - mitchellh/zig-graph

README

        
# zig-graph

A Zig library for directed graph data structures and associated algorithms.

This library can be used for acyclic and cyclic graphs and unweighted and weighted

edges. This library requires Zig 0.9+.

**Warning: This is literally the first piece of Zig code I've ever written

in my life.** I'm using this project as a way to learn how to do things in

Zig, what is idiomatic, what isn't, etc. Feedback is very welcome on how

I can improve and I expect to alter the library a bit as I do so.  There is

also a lot of room for improvement in performance by various measures.

## Features

* Directed edges

* Cycle detection

* Strongly connected components

* Cheap edge reversal

* Depth-first traversal

#### TODO

* Vertex iterator

* Edge iterator

* Dijkstra for single-source shortest path w/ edge-weighting

* Kahn for topological sorting

* Shortest path given a topological sort

* String marshaling for easier debugging

* "Unmanaged" graph so allocator can be sent to each op

## Example

```zig

const std = @import("std");

const graph = @import("graph");

pub fn main() void {

	// Create a directed graph type for strings.

	const Graph = graph.DirectedGraph([]const u8, std.hash_map.StringContext);

	// Initialize using some allocator

	var g = Graph.init(std.debug.global_allocator);

	defer g.deinit();

	// Add some vertices

	try g.add("A");

	try g.add("B");

	try g.add("C");

	// Add some edges with weights. For unweighted edges just make all

	// weights the same value.

	try g.addEdge("A", "B", 5);

	try g.addEdge("A", "C", 2);

	try g.addEdge("B", "C", 2);

	try g.addEdge("C", "B", 3);

	// We can detect cycles

	if (g.cycles()) |cycles| {

		defer cycles.deinit();

		std.log.info("there are {d} cycles", .{cycles.count()});

		return;

	}

	// We can do a depth-first search through iteration.

	var dfsIter = try g.dfsIterator("B");

	while (dfsIter.next()) |id| {

		std.log.info("{}", .{g.lookup(id).?});

	}

	dfsIter.deinit();

	// We can easily reverse the graph if we want.

	const reversed = g.reverse();

	// ... and more

}

```