weighted directed graph data structure written in Object-C
Objective-C
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Permalink
Failed to load latest commit information.
Class Update Graph.m Jan 14, 2015
Test
LICENSE.txt
README.rdoc

README.rdoc

digraph

This is An implementation of weighted directed graph data structure written in Object-C. It uses Dijkstra’s algorithm to find the shortest path between a source node and target node.

Note

The code is pretty well tested. Currently all tests pass, but it is not yet battle tested, and it is probably not perfect.

I don't know how good the performance for this is, but you should know that I didn't spend anytime on performance.

You should probably use this library as a starting point for your own graph data structure, and tweak / fix as you like.

Usage

Here is a quick example on how to use this lib.

#import "Graph.h"

int main(){
    Graph* graph;
    GraphNode *ns, *nt, *n1, *n2, *n3;
    GraphEdge *nsn1, *nsn2, *nsn3, *n1nt, *n2nt, *n3nt;

    // create the graph
    graph = [Graph graph];

    // add some nodes
    ns = [GraphNode nodeWithValue:@"ns"];
    nt = [GraphNode nodeWithValue:@"nt"];
    n1 = [GraphNode nodeWithValue:@"n1"];
    n2 = [GraphNode nodeWithValue:@"n2"];
    n3 = [GraphNode nodeWithValue:@"n3"];

    // add some edges
    nsn1 = [graph addEdgeFromNode:ns toNode:n1 withWeight:7.0f];
    nsn2 = [graph addEdgeFromNode:ns toNode:n2 withWeight:9.0f];
    nsn3 = [graph addEdgeFromNode:ns toNode:n3 withWeight:14.0f];
    n1nt = [graph addEdgeFromNode:n1 toNode:nt withWeight:10.0f];
    n2nt = [graph addEdgeFromNode:n2 toNode:nt withWeight:9.0f];
    n3nt = [graph addEdgeFromNode:n3 toNode:nt withWeight:1.0f];

    // The graph now look like this:
    //
    //      /------7------> n1 ------10-----\
    //      |                               |
    //      |                               |
    //      |                               |
    // ns --|------9------> n2 ------9------|--------> nt
    //      |                               |
    //      |                               |
    //      |                               |
    //      \------14-----> n3 ------1------/
    //

    // find the shortest path from ns to nt
    NSArray* path = [graph shortestPath:ns to:nt];
    // The result should be:
    //  [n3, nt]

    return 0;
}

Copyright

Copyright © 2011 Aaron Qian. See LICENSE.txt for further details.