gistfile1.cpp

Graph METISGraphReader::read(std::string path) {

	METISParser parser(path);

	std::tuple<count, count, index> header = parser.getHeader();
	count n = std::get<0>(header);
	count m = std::get<1>(header);
	index weighted = std::get<2>(header);
	//std::tie(n,m,weighted) = header;
	// TODO: std::tie(n, m, weighted) = header

	Graph G(n);

	std::string graphName = Aux::StringTools::split(Aux::StringTools::split(path, '/').back(), '.').front();

	G.setName(graphName);

	std::cout << "[BEGIN] reading graph G(n=" << n << ", m=" << m << ") from METIS file: " << std::flush;	// progress bar follows

	double p = 0.0; // percentage for progress bar
	node u = 0; // begin with 0

	if (weighted == 0) {
		while (parser.hasNext()) {
			std::vector<node> adjacencies = parser.getNext();
			for (index i=0; i < adjacencies.size(); i++) {

				node v = adjacencies[i] - 1; 	// METIS-indices are 1-based
				assert (v >= 0);
				if (u <= v) { // self-loops are allowed
					G.addEdge(u, v);
				}
			}
			u++; // next node
			if ((u % ((n + 10)/10)) == 0) {
				p = ((double) (u-1) / (double) n) * 100;
				std::cout << p << "% " << std::flush;
			}
		}
		std::cout << "[DONE]" << std::endl;
		return G;
	} else {
		while (parser.hasNext()) {

			std::vector<std::pair<node,double>> adjacencies = parser.getNextWithWeights();

			for (index i=0; i < adjacencies.size(); i++) {
				node v = adjacencies[i].first- 1; 	// METIS-indices are 1-based
				assert (v >= 0);
				if (u <= v) { // self-loops are allowed
					G.addEdge(u, v);
					G.setWeight(u, v, adjacencies[i].second);
					assert(adjacencies[i].second > 0);
				}
			}
			u += 1; // next node
			if ((u % ((n + 10)/10)) == 0) {
				p = ((double) (u-1) / (double) n) * 100;
				std::cout << p << "% " << std::flush;
			}
		}
		std::cout << "[DONE]" << std::endl;
		return G;
	}
}