New graph data structures in graph.cpp

graph/alt_graph.cpp

+// Old implementation, maybe superior for some graphs.
+
+//=============================================================================
+// Class for Graph Nodes (one line of the adjacency matrix):
+//=============================================================================
+
+class Node {
+	public:
+
+	// Constructor:
+	Node(int graph_num_nodes)
+	{
+		num_nodes_ = graph_num_nodes;
+		int bytes = (num_nodes_ + BYTE_SIZE - 1) / BYTE_SIZE;
+		connections_ = new char[bytes];
+		char *p = connections_;
+		for(int i = bytes; i > 0; i--)
+			*p++ = '\0';
+	}
+
+	// Accessor Functions:
+	inline int num_nodes() const { return num_nodes_; }
+
+	// Store edge in adjacency matrix:
+	void store_connection(int to) {
+		// Check nodes:
+		if(to <= 0 || to > num_nodes_) {
+			std::cerr << "Invalid to node: " << to << "\n";
+			exit(3);
+		}
+
+		// Determine position in adjacency matrix:
+		long index = to - 1;
+		int bit = index % 8;
+		index = index / 8;
+
+		// Set bit:
+		connections_[index] |= (0x1) << bit;
+	}
+
+	// Check whether edge exists:
+	bool connection_exists(int to) const {
+		// Check node:
+		if(to <= 0 || to > num_nodes_) {
+			std::cerr << "Invalid to node: " << to << "\n";
+			exit(4);
+		}
+
+		// Determine position in adjacency matrix:
+		long index = to - 1;
+		int bit = index % 8;
+		index = index / 8;
+
+		// Check bit:
+		return (connections_[index] & ((0x1) << bit)) != 0;
+	}
+
+	// Copy other node into this node:
+	void copy(Node *node) {
+		if(node->num_nodes_ != num_nodes_) {
+			std::cerr << "Can copy only node of same size!\n";
+			exit(5);
+		}
+		int bytes = (num_nodes_ + BYTE_SIZE - 1) / BYTE_SIZE;
+		char *to = connections_;
+		char *from = node->connections_;
+		while(bytes-- > 0)
+			*to++ = *from++;
+	}
+
+	// Attributes:
+	private:
+	int num_nodes_;
+	char *connections_;
+};
+
+//-----------------------------------------------------------------------------
+// Pointer Type for Node Data:
+//-----------------------------------------------------------------------------
+
+typedef Node *node_t;
+
+#define NODE_NULL (static_cast<node_t>(0))
+
+
+//=============================================================================
+// Class for Graphs (contains adjacency matrix):
+//=============================================================================
+
+class Graph {
+	public:
+
+	// Constructor:
+	Graph(int graph_num_nodes)
+	{
+		num_nodes_ = graph_num_nodes;
+		nodes_ = new node_t[num_nodes_];
+		for(int i = 0; i < graph_num_nodes; i++)
+			nodes_[i] = new Node(graph_num_nodes);
+	}
+
+	// Accessor Functions:
+	inline int num_nodes() const { return num_nodes_; }
+	inline node_t node(int i) const { return nodes_[i-1]; }
+
+	// Store edge in adjacency matrix:
+	void store_edge(int from, int to) {
+		// Check nodes:
+		if(from <= 0 || from > num_nodes_) {
+			std::cerr << "Invalid from node: " << from << "\n";
+			exit(6);
+		}
+		if(to <= 0 || to > num_nodes_) {
+			std::cerr << "Invalid to node: " << to << "\n";
+			exit(7);
+		}
+
+		// Store edge in adjacency matrix:
+		long index = from - 1;
+		nodes_[index]->store_connection(to);
+	}
+
+	// Check whether edge exists:
+	bool edge_exists(int from, int to) const {
+		// Check nodes:
+		if(from <= 0 || from > num_nodes_) {
+			std::cerr << "Invalid from node: " << from << "\n";
+			exit(8);
+		}
+		if(to <= 0 || to > num_nodes_) {
+			std::cerr << "Invalid to node: " << to << "\n";
+			exit(9);
+		}
+
+		// Look up edge in adjacency matrix:
+		long index = from - 1;
+		return nodes_[index]->connection_exists(to);
+	}
+
+	// Copy a graph (of the same size) into this graph:
+	void copy(Graph *g)
+	{
+		if(g->num_nodes_ != num_nodes_) {
+			std::cerr << "Can copy only graph of same size!\n";
+			exit(10);
+		}
+		for(int i = 0; i < num_nodes_; i++)
+			nodes_[i]->copy(g->nodes_[i]);
+	}
+
+	// Attributes:
+	private:
+	int num_nodes_;
+	node_t *nodes_;
+};
+
+//-----------------------------------------------------------------------------
+// Pointer Type for Graph Data:
+//-----------------------------------------------------------------------------
+
+typedef Graph *graph_t;
+
+#define GRAPH_NULL (static_cast<graph_t>(0))
+