Function QueryGraph_MatrixRepresentation

src/graph/query_graph.c:730–770

}

GrB_Matrix QueryGraph_MatrixRepresentation
(
	const QueryGraph *qg
) {
	ASSERT(qg != NULL);

	// make a clone of the given graph as we're about to modify it
	QueryGraph *qg_clone = QueryGraph_Clone(qg);

	// give an ID for each node, abuse of `labelID`
	uint node_count = QueryGraph_NodeCount(qg_clone);
	for(uint i = 0; i < node_count; i++) {
		QGNode *n = qg_clone->nodes[i];
		if(QGNode_LabelCount(n) == 0) QGNode_AddLabel(n, "", i);
		else n->labelsID[0] = i;
	}

	GrB_Matrix m;   // matrix representation of QueryGraph
	GrB_Info res = GrB_Matrix_new(&m, GrB_BOOL, node_count, node_count);
	UNUSED(res);
	ASSERT(res == GrB_SUCCESS);

	// build matrix representation of query graph
	for(uint i = 0; i < node_count; i++) {
		const QGNode *n = qg_clone->nodes[i];
		GrB_Index src = QGNode_GetLabelID(n, 0);
		uint outgoing_degree = QGNode_OutgoingDegree(n);

		for(uint j = 0; j < outgoing_degree; j++) {
			const QGEdge *e = n->outgoing_edges[j];
			GrB_Index dest = QGNode_GetLabelID(e->dest, 0);

			// populate `m`
			res = GrB_Matrix_setElement_BOOL(m, true, src, dest);
			ASSERT(res == GrB_SUCCESS);
		}
	}

	QueryGraph_Free(qg_clone);
	return m;
}

void QueryGraph_Print
(