int dfs(Graph * graph, List * ordered)
{
DfsVertex *vertex;
ListElmt *element;
/*****************************************************************************
* *
* Initialize all of the vertices in the graph. *
* *
*****************************************************************************/
for (element = list_head(&graph_adjlists(graph)); element != NULL;
element = list_next(element)) {
vertex = ((AdjList *) list_data(element))->vertex;
vertex->color = white;
}
/*****************************************************************************
* *
* Perform depth-first search. *
* *
*****************************************************************************/
list_init(ordered, NULL);
for (element = list_head(&graph_adjlists(graph)); element != NULL;
element = list_next(element)) {
/**************************************************************************
* *
* Ensure that every component of unconnected graphs is searched. *
* *
**************************************************************************/
vertex = ((AdjList *) list_data(element))->vertex;
if (vertex->color == white) {
if (dfs_main
(graph, (AdjList *) list_data(element),
ordered) != 0) {
list_destroy(ordered);
return -1;
}
}
}
return 0;
}
static int dfs_main(Graph * graph, AdjList * adjlist, List * ordered)
{
AdjList *clr_adjlist;
DfsVertex *clr_vertex, *adj_vertex;
ListElmt *member;
/*****************************************************************************
* Color the vertex gray and traverse its adjacency list. *
*****************************************************************************/
((DfsVertex *) adjlist->vertex)->color = gray;
for (member = list_head(&adjlist->adjacent); member != NULL; member =
list_next(member)) {
/**************************************************************************
* Determine the color of the next adjacent vertex. *
**************************************************************************/
adj_vertex = list_data(member);
if (graph_adjlist(graph, adj_vertex, &clr_adjlist) != 0)
return -1;
clr_vertex = clr_adjlist->vertex;
/**************************************************************************
* Move one vertex deeper when the next adjacent vertex is white. *
**************************************************************************/
if (clr_vertex->color == white) {
if (dfs_main(graph, clr_adjlist, ordered) != 0)
return -1;
}
}
/*****************************************************************************
* Color the current vertex black and make it first in the list. *
*****************************************************************************/
((DfsVertex *) adjlist->vertex)->color = black;
if (list_ins_next(ordered, NULL, (DfsVertex *) adjlist->vertex) != 0)
return -1;
return 0;
}
int main(){
int i,j;
initialize_graph(3,2);
add_edge(0,1);
add_edge(1,2);
//add_edge(2,0);
//add_edge(0,3);
//add_edge(3,4);
dfs_main();
return 0;
}
