Example Dijkstra algorithm (shortest path problem) implementation written in Objective-C.
#import <Dijkstra/Dijkstra.h>
// Define the nodes
DJKNode *Brno = [DJKNode nodeWithID:@"Brno"];
DJKNode *Praha = [DJKNode nodeWithID:@"Praha"];
DJKNode *Ostrava = [DJKNode nodeWithID:@"Ostrava"];
DJKNode *Pardubice = [DJKNode nodeWithID:@"Pardubice"];
DJKNode *Kolin = [DJKNode nodeWithID:@"Kolin"];
DJKNode *Plzen = [DJKNode nodeWithID:@"Plzen"];
DJKNode *Adamov = [DJKNode nodeWithID:@"Adamov"];
// Define the graph edges
NSArray<DJKEdge *> *edges = @[
[DJKEdge edgeFromNode:Ostrava toNode:Brno cost:180],
[DJKEdge edgeFromNode:Praha toNode:Ostrava cost:420],
[DJKEdge edgeFromNode:Pardubice toNode:Brno cost:110],
[DJKEdge edgeFromNode:Pardubice toNode:Praha cost:90],
[DJKEdge edgeFromNode:Pardubice toNode:Plzen cost:140],
[DJKEdge edgeFromNode:Pardubice toNode:Ostrava cost:290],
[DJKEdge edgeFromNode:Plzen toNode:Praha cost:70],
[DJKEdge edgeFromNode:Adamov toNode:Adamov cost:0],
];
// Initialize the graph itself
DJKGraph *G = [DJKGraph graphWithEdges:edges];
// Look for shortest paths and print'em
NSLog(@"%@", [G shortestPathFromNode:Praha toNode:Ostrava]);
// [Praha, Pardubice, Ostrava]
NSLog(@"%@", [G shortestPathFromNode:Ostrava toNode:Plzen]);
// [Ostrava, Pardubice, Plzen]
NSLog(@"%@", [G shortestPathFromNode:Ostrava toNode:Ostrava]);
// [Ostrava]
NSLog(@"%@", [G shortestPathFromNode:Brno toNode:Kolin]);
// []
Dijkstra example is released under the MIT license. See the LICENSE file for details.