/// D-MST
struct Edge
{
int u,v,w;
};Edge e[maxn];int en;
int in[25100];
int pre[25100],ID[25100],vis[25100];
/// D-MST 点的标号必须是0~N-1,不能改成0~N或1~N
int D_MST(int rt,int n,int m)
{
int res=0;
while(1){
REP(i,0,n-1) in[i]=INF;
REP(i,1,m){
int u=e[i].u,v=e[i].v,w=e[i].w;
if(w<in[v]&&u!=v){
pre[v]=u;
in[v]=w;
}
}
REP(i,0,n-1){
if(i==rt) continue;
if(in[i]==INF) return -1;
}
int cntnode=0;
memset(ID,-1,sizeof(ID));
memset(vis,-1,sizeof(vis));
in[rt]=0;
REP(i,0,n-1){
res+=in[i];
int v=i;
while(vis[v]!=i&&ID[v]==-1&&v!=rt){
vis[v]=i;
v=pre[v];
}
if(v!=rt&&ID[v]==-1){
for(int u=pre[v];u!=v;u=pre[u]) ID[u]=cntnode;
ID[v]=cntnode++;
}
}
if(cntnode==0) break;
REP(i,0,n-1) if(ID[i]==-1) ID[i]=cntnode++;
REP(i,1,m){
int v=e[i].v;
e[i].u=ID[e[i].u];
e[i].v=ID[e[i].v];
if(e[i].u!=e[i].v) e[i].w-=in[v];
}
n=cntnode;
rt=ID[rt];
}
return res;
}
