void dijkstra(int src, IV &dis) {
IIS q;
dis = IV(n, INF);
BV flg(n);
dis[src] = 0;
q.insert(II(0, src));
while (! q.empty()) {
int v = q.begin()->second;
q.erase(q.begin());
if (flg[v]) continue;
flg[v] = true;
cFor (EL, e, adj[v]) {
int d = dis[v] + e->w;
if (!flg[e->v] && d < dis[e->v]) {
if (dis[e->v] != INF) q.erase(II(dis[e->v], e->v));
dis[e->v] = d;
q.insert(II(dis[e->v], e->v));
}
}
}
void prim_min(ELV &g, int src) {
IIS q;
IV dis(n, INF);
BV flg(n);
dis[src] = 0;
q.insert(II(0, src));
while (! q.empty()) {
int d = q.begin()->first;
int v = q.begin()->second;
q.erase(q.begin());
if (flg[v]) continue;
flg[v] = true;
cFor (EL, e, g[v])
if (!flg[e->v] && e->w < dis[e->v]) {
if (dis[e->v] != INF) q.erase(II(dis[e->v], e->v));
dis[e->v] = e->w;
q.insert(II(dis[e->v], e->v));
}
}
}
int prim_mst(int src) {
IIS q;
IV dis(n, INF);
BV flg(n);
dis[src] = 0;
q.insert(II(0, src));
int mst = 0;
while (! q.empty()) {
int d = q.begin()->first;
int v = q.begin()->second;
q.erase(q.begin());
if (flg[v]) continue;
flg[v] = true;
mst += d;
For (EL, e, adj[v])
if (!flg[e->v] && e->w < dis[e->v]) {
dis[e->v] = e->w;
q.insert(II(dis[e->v], e->v));
}
}
return mst;
}
void test_case()
{
int n = rand() % (MAXN - 2) + 3;
int MaxEdges = min(n*(n-1)/2, MAXM);
int m = rand() % (MaxEdges + 1);
if (m < n - 1) m = n - 1;
printf("\n%d %d\n", n, m);
IV ls;
IIS s;
for (int i = 0; i < n; ++i)
ls.push_back(i);
random_shuffle(ls.begin(), ls.end());
printf("%d %d\n", ls[0], ls[1]); --m;
int u = ls[0], v = ls[1];
if (u > v) swap(u, v);
s.insert(II(u, v));
for (int i = 2; i < n; ++i) {
u = ls[rand() % i], v = ls[i];
printf("%d %d\n", u, v); --m;
if (u > v) swap(u, v);
s.insert(II(u, v));
}
while (m--) {
int u, v;
do {
u = rand() % n;
v = rand() % n;
if (u > v) swap(u, v);
} while (u == v || s.find(II(u, v)) != s.end());
s.insert(II(u, v));
if (rand() % 2 == 0) swap(u, v);
printf("%d %d\n", u, v);
}
}
