Пример #1
0
        // Single step of recursive DFS.
        private static void dfsRecursiveStep <TVertexId, TVertexProperty, TEdgeProperty>(
            this IGraph <TVertexId, TVertexProperty, TEdgeProperty> graph, IDfsStrategy <TVertexId> strategy,
            DfsRecursiveState <TVertexId> state)
        {
            Vertex <TVertexId> vertex = state.vertex;

            state.onEntry(vertex);
            strategy.OnEntry(vertex);

            foreach (Vertex <TVertexId> neighbour in graph.GetNeighbours(vertex))
            {
                if (!state.reached.ContainsKey(neighbour))
                {
                    strategy.OnNextVertex(vertex, neighbour);
                    state.vertex = neighbour;
                    graph.dfsRecursiveStep(strategy, state);
                }
                else if (state.reached[neighbour] == state.iteration)
                {
                    strategy.OnEdgeToVisited(vertex, neighbour);
                }
            }

            strategy.OnExit(vertex);
            state.onExit(vertex);
        }
Пример #2
0
        /// <summary>Recursive deph-first-search algorithm.</summary>
        /// <param name="graph">a graph</param>
        /// <param name="strategy">a searching strategy</param>
        /// <param name="roots">starting vertices</param>
        /// <returns>enumerable of visited vertices</returns>
        public static IEnumerable <Vertex <TVertexId> > DfsRecursive <TVertexId, TVertexProperty, TEdgeProperty>(
            this IGraph <TVertexId, TVertexProperty, TEdgeProperty> graph, IDfsStrategy <TVertexId> strategy,
            IEnumerable <Vertex <TVertexId> > roots)
        {
            var state = new DfsRecursiveState <TVertexId>();

            foreach (Vertex <TVertexId> root in roots)
            {
                if (!state.reached.ContainsKey(root))
                {
                    strategy.ForRoot(root);
                    state.vertex = root;
                    graph.dfsRecursiveStep(strategy, state);
                    ++state.iteration;
                }
            }

            return(state.reached.Keys);
        }