+xbt_dynar_t xbt_graph_get_nodes(xbt_graph_t g)
+{
+ return g->nodes;
+}
+xbt_dynar_t xbt_graph_get_edges(xbt_graph_t g)
+{
+ return g->edges;
+}
+
+xbt_node_t xbt_graph_edge_get_source(xbt_edge_t e)
+{
+
+ return e->src;
+}
+xbt_node_t xbt_graph_edge_get_target(xbt_edge_t e)
+{
+ return e->dst;
+}
+int xbt_get_node_index(xbt_graph_t g, xbt_node_t n)
+{
+
+ int cursor=0;
+ xbt_node_t tmp;
+ xbt_dynar_foreach(g->nodes,cursor,tmp)
+ {
+ if (tmp==n)
+ break;
+ }
+ return (cursor-1);
+}
+
+void xbt_graph_edge_set_length(xbt_edge_t e, double length)
+{
+ e->length=length;
+
+}
+double xbt_graph_edge_get_length(xbt_edge_t e)
+{
+ return e->length;
+}
+
+
+/*construct the adjacency matrix corresponding to a graph,
+ the weights are the distances between nodes
+ */
+double* xbt_graph_get_length_matrix(xbt_graph_t g)
+{
+ fprintf(stderr,"%s","START GET LENGTHS\n" );
+ int cursor = 0;
+ int in_cursor = 0;
+ int idx,i;
+ unsigned long n;
+ xbt_edge_t edge = NULL;
+ xbt_node_t node;
+ double* d=NULL;
+
+ # define D(u,v) d[(u)*n+(v)]
+ n = xbt_dynar_length(g->nodes);
+
+ d = (double*)xbt_malloc(n*n*(sizeof(double)));
+
+ for (i=0;i<n*n;i++)
+ {
+ d[i]=-1.0;
+ }
+
+
+ xbt_dynar_foreach(g->nodes,cursor,node)
+ {fprintf(stderr,"CURSOR: %d\n",cursor );
+ in_cursor=0;
+ D(cursor-1,cursor-1)=0;
+ xbt_dynar_foreach(node->in,in_cursor,edge)
+ {fprintf(stderr,"EDGE IN: %s\n",(char*)edge->data );
+fprintf(stderr,"EDGE DST: %s\n",(char*)edge->dst->data );
+ idx = xbt_get_node_index(g,edge->dst);
+ fprintf(stderr,"IDX: %d\n",idx );
+fprintf(stderr,"EDGE ADR: %x\n",(int)edge );
+fprintf(stderr,"EDGE LENGTH: %le\n", edge->length );
+ D(cursor-1,idx) = edge->length;
+ }
+ }
+ fprintf(stderr,"BEFORE RETURN\n" );
+
+# undef D
+
+return d;
+}
+
+ /* calculate all-pairs shortest paths */
+/* the shortest distance between node i and j are stocked in distances[i][j] */
+void xbt_floyd_algorithm(xbt_graph_t g, double* adj,double* d, xbt_node_t* p)
+{
+ int i,j,k;
+ unsigned long n;
+ n = xbt_dynar_length(g->nodes);
+
+# define D(u,v) d[(u)*n+(v)]
+# define P(u,v) p[(u)*n+(v)]
+
+
+
+ for(i=0;i<n*n;i++)
+ {
+ d[i]=adj[i];
+ }
+ for(i=0;i<n;i++)
+ {
+ for(j=0;j<n;j++)
+ {
+ if(D(i,j)!=-1) P(i,j)=xbt_dynar_get_ptr (g->nodes,i) ;
+ }
+ }
+
+ for(k=0;k<n;k++)
+ {
+ for(i=0;i<n;i++)
+ {
+ for(j=0;j<n;j++)
+ {
+ if((D(i,k)!=-1) && (D(k,j)!=-1))
+ {
+ if((D(i,j)==-1) || (D(i,j) > D(i,k)+D(k,j)))
+ {
+ D(i,j) = D(i,k)+D(k,j) ;
+ P(i,j) = P(k,j);
+ }
+ }
+ }
+ }
+ }
+# undef P
+# undef D
+}
+
+/*computes all-pairs shortest paths*/
+xbt_node_t* xbt_graph_shortest_paths(xbt_graph_t g)
+{
+ xbt_node_t* p;
+ xbt_node_t* r;
+ int i,j,k;
+ unsigned long n;
+
+ double* adj=NULL;
+ double* d=NULL;
+
+# define P(u,v) p[(u)*n+(v)]
+# define R(u,v) r[(u)*n+(v)]
+
+ n = xbt_dynar_length(g->nodes);
+ adj= xbt_graph_get_length_matrix(g);
+ xbt_floyd_algorithm(g,adj,d,p);
+
+ for(i=0;i<n;i++)
+ {
+ for(j=0;j<n;j++)
+ {
+ k=j;
+ while((P(i,k))&&( xbt_get_node_index(g,P(i,k))!=i))
+ {
+ k = xbt_get_node_index(g,P(i,k));
+ }
+ if(P(i,j))
+ {
+ R(i,j)=(xbt_node_t)xbt_dynar_get_ptr(g->nodes,k);
+ }
+ }
+ }
+# undef R
+# undef P
+
+ xbt_free(d);
+ xbt_free(p);
+ return r;
+}
+
