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| #include<iostream>
#include<vector>
#include<stack>
#include<cmath>
#include<algorithm>
#include<cstring>
#include<cstdio>
using namespace std;
#define N 500005
int n,m,q[N],fa[N][20],g[N][20],dfn[N],rnd[N],cnt=0,dep[N];
vector<int> mp[N],mp1[N];
long long h[N],d[N];
struct Node
{
int u,dfn;
}keys[N];
bool cmp(Node a,Node b)
{
return a.dfn<b.dfn;
}
struct node
{
int v,w;
}edge[N<<2],vt[N<<2];
int sta[N<<3];
int cnt_=0;
void dfs(int x)
{
dep[x]=dep[fa[x][0]]+1;
dfn[x]=++cnt;
rnd[cnt]=x;
for(int i=1;i<=19;i++)
{
fa[x][i]=fa[fa[x][i-1]][i-1];
g[x][i]=min(g[fa[x][i-1]][i-1],g[x][i-1]);
}
for(int i=0;i<mp[x].size();i++)
{
if(edge[mp[x][i]].v==fa[x][0]) continue;
fa[edge[mp[x][i]].v][0]=x;
g[edge[mp[x][i]].v][0]=edge[mp[x][i]].w;
dfs(edge[mp[x][i]].v);
}
}
long long lca(int u,int v)
{
if(dep[u]<dep[v]) swap(u,v);
while(dep[u]>dep[v])
{
u=fa[u][(int)log2(dep[u]-dep[v])];
}
if(u==v) return u;
for(int i=log2(dep[u]);i>=0;i--)
if(fa[u][i]!=fa[v][i])
u=fa[u][i],v=fa[v][i];
return fa[u][0];
}
long long query(int u, int v) {
int ans = 0x3f3f3f3f;
while (dep[u] > dep[v]) {
ans = min(ans, g[u][(int)log2(dep[u] - dep[v])]);
u = fa[u][(int)log2(dep[u] - dep[v])];
}
return ans;
}
void dp(int u)
{
for(int i=0;i<mp1[u].size();i++)
{
int v=vt[mp1[u][i]].v;
int w=vt[mp1[u][i]].w;
dp(v);
if(h[v])
d[u]+=w;
else
d[u]+=min((long long)w,d[v]);
h[v]=0;d[v]=0;
}
mp1[u].clear();
}
int main()
{
cin>>n;
memset(g,0x3f,sizeof(g));
for(int i=1;i<n;i++)
{
int u,v,w;
cin>>u>>v>>w;
mp[u].push_back(i*2-1);
edge[i*2-1].v=v;edge[i*2-1].w=w;
mp[v].push_back(i*2);
edge[i*2].v=u;edge[i*2].w=w;
}
dfs(1);
scanf("%d",&m);
while(m--)
{
int k;
scanf("%d",&k);
for(int i=1;i<=k;i++)
{
cin>>keys[i].u;
h[keys[i].u]=1;
keys[i].dfn=dfn[keys[i].u];
}
stack<int> s;
sort(keys+1,keys+k+1,cmp);
s.push(1);
for(int i=1;i<=k;i++)
{
int u=keys[i].u;
int la=lca(u,s.top());
while(s.top()!=la)
{
int tmp=s.top();s.pop();
if(dfn[s.top()]<dfn[la])
s.push(la);
mp1[s.top()].push_back(++cnt_);
vt[cnt_].v=tmp;
vt[cnt_].w=query(tmp,s.top());
}
s.push(u);
}
while(s.top()!=1)
{
int tmp=s.top();
s.pop();
mp1[s.top()].push_back(++cnt_);
vt[cnt_].v=tmp;
vt[cnt_].w=query(tmp,s.top());
}
dp(1);
cout<<d[1]<<endl;
d[1]=0;
cnt_=0;
}
return 0;
}
|
