74 	NODE *n_next;			/* next node in graph */
89 static NODE *graph, **cycle_buf, **longest_cycle;  variable
144 	/* parse input and build the graph */  in main()
188  * add an arc from node s1 to node s2 in the graph.  If s1 or s2 are not in
189  * the graph, then add them.
225 /* Find a node in the graph (insert if not found) and return a pointer to it. */
261 	if ((n->n_next = graph) != NULL)  in get_node()
262 		graph->n_prevp = &n->n_next;  in get_node()
263 	n->n_prevp = &graph;  in get_node()
264 	graph = n;  in get_node()
283 	for (n = graph; n != NULL; n = n->n_next)  in clear_cycle()
287 /* do topological sort on graph */
294 	while (graph != NULL) {  in tsort()
297 		 * if there are any nodes still in the graph, then there is  in tsort()
301 			for (cnt = 0, n = graph; n != NULL; n = next) {  in tsort()
308 		} while (graph != NULL && cnt);  in tsort()
310 		if (graph == NULL)  in tsort()
319 			for (cnt = 0, n = graph; n != NULL; n = n->n_next)  in tsort()
326 		for (n = graph; n != NULL; n = n->n_next)  in tsort()
350 /* print node and remove from graph (does not actually free node) */
375 	 * avoid infinite loops and ignore portions of the graph known  in find_cycle()