public static ZDDNode CreateRootNode(int number_of_vertices) {
ZDDNode node = new ZDDNode();
node.SetNextId();
node.deg = new int[number_of_vertices + 1];
node.comp = new int[number_of_vertices + 1];
node.compCount = new int[number_of_vertices + 1];
node.mate = new int[number_of_vertices + 1];
for(int i = 1; i <= number_of_vertices; ++i) {
node.deg[i] = 0;
node.comp[i] = i;
node.compCount[i] = 1;
node.mate[i] = 0;
}
return node;
}