/*
* Function that examines for an opportunity to discover a new shortest path
* from u to v, using w.
*/
void di_examine(int n, int u, int v, int w, float* dist, float* graph,
int* p, int* q, std::vector<int>* L, std::vector<int>* R,
std::list<int>* bucket_heap, int* b_num,
std::list<int>::iterator* iters) {
if (dist[u*n + v] + dist[v*n + w] < dist[u*n + w]) {
dist[u*n + w] = dist[u*n + v] + dist[v*n + w];
// If it's never been inserted, insert, else decrease.
if (p[u*n + w] == -1) {
heap_insert(bucket_heap, b_num, u*n + w, dist[u*n + w], n, iters);
} else {
heap_decrease(bucket_heap, b_num, u*n + w, dist[u*n + w], n, iters);
}
p[u*n + w] = p[u*n + v];
q[u*n + w] = q[v*n + w];
}
}
int main() {
int n, m; scanf("%d%d", &n, &m);
edge es[2*m];
for (int i = 0; i < m; i++) {
int vi, ui, w; scanf("%d%d%d", &vi, &ui, &w);
vertex *v = &vs[vi], *u = &vs[ui];
es[2*i] = (edge){u, w, v->a}; v->a = &es[2*i];
es[2*i+1] = (edge){v, w, u->a}; u->a = &es[2*i+1];
}
const int inf = (int)1e9;
for (vertex *v = vs; v != vs+n; v++) {
v->i = v - vs;
v->d = inf;
v->b = false;
heap_insert(v);
}
int s; scanf("%d", &s);
vs[s]->d = 0;
for (int i = 0; i < n; i++) {
vertex *v = heap_extract();
v->b = true;
for (edge *e = v->a; e != NULL; e = e->n) {
vertex *u = e->v;
if (!u->b && v->d + e->w < u->d) {
u->d = v->d + e->w;
heap_decrease(u);
}
}
}
return 0;
}
