void dijkstra(node& p)
{
if ( !ok(p) || stop || isvisited(p) )
return;
// neighbors
node a(p.x+1, p.y); // move right
node b(p.x, p.y+1); // move down
node c(p.x, p.y-1); // move up
node D(p.x-1, p.y); // move left
// tentative distances
uint32_t d = getdist(p);
uint32_t da = sum(d, getcost(a));
uint32_t db = sum(d, getcost(b));
uint32_t dc = sum(d, getcost(c));
uint32_t dd = sum(d, getcost(D));
// update distances
if ( !isvisited(a) && da < getdist(a) ) setdist(a, da);
if ( !isvisited(b) && db < getdist(b) ) setdist(b, db);
if ( !isvisited(c) && dc < getdist(c) ) setdist(c, dc);
if ( !isvisited(D) && dd < getdist(D) ) setdist(D, dd);
// mark this node
setvisited(p);
// has all dest nodes been visited?
if ( allvisited() ) {
// target node is lower right
final = getdist(node(xmax-1, ymax-1));
stop = true;
return;
}
void dijkstra(node& p)
{
if ( !ok(p) || stop || isvisited(p) )
return;
// neighbors
node a(p.x+1, p.y);
node b(p.x, p.y+1);
// tentative distances
uint32_t d = getdist(p);
uint32_t da = sum(d, getcost(a));
uint32_t db = sum(d, getcost(b));
// update distances
if ( !isvisited(a) && da < getdist(a) ) setdist(a, da);
if ( !isvisited(b) && db < getdist(b) ) setdist(b, db);
// mark this node
setvisited(p);
// has dest node been visited?
if ( isvisited(node(xmax-1, ymax-1)) ) {
// ...
uint32_t final = getdist(node(xmax-1, ymax-1));
printf("Finished with distance %u\n", final);
stop = true;
return;
}
static void update(Dict_t * Q, Agnode_t * dest, Agnode_t * src, double len)
{
double newlen = getdist(src) + len;
double oldlen = getdist(dest);
if (oldlen == 0) { /* first time to see dest */
setdist(dest, newlen);
dtinsert(Q, dest);
} else if (newlen < oldlen) {
dtdelete(Q, dest);
setdist(dest, newlen);
dtinsert(Q, dest);
}
}
void dijkstra(Dict_t * Q, Agraph_t * G, Agnode_t * n)
{
Agnode_t *u;
Agedge_t *e;
pre(G);
setdist(n, 1);
dtinsert(Q, n);
while ((u = extract_min(Q))) {
for (e = agfstedge(u); e; e = agnxtedge(e, u)) {
update(Q, e->node, u, getlength(e));
}
}
post(G);
}
