bzoj 3611: [Heoi2014]大工程

 #include<iostream>
 #include<cstdio>
 #include<cstring>
 #include<algorithm>
 #define M 2000009
 #define inf 0x7ffffff
 #define ll long long
 using namespace std;
 int n,head[M],next[M],u[M],cnt,head1[M],next1[M],u1[M],fa[M][],deep[M],m,dfn[M],T,v[M];
 int h[M],st[M],mn[M],mx[M],size[M],mx1,mi1,v1[M];
 ll cn1,sum[M];
 void jia(int a1,int a2)
 {
     cnt++;
     next[cnt]=head[a1];
     head[a1]=cnt;
     u[cnt]=a2;
     return;
 }
 void jia2(int a1,int a2)
 {
     if(a1==a2)
       return;
     cnt++;
     next1[cnt]=head1[a1];
     head1[a1]=cnt;
     u1[cnt]=a2;
     v1[cnt]=deep[a2]-deep[a1];
     return;
 }
 bool cmp(int a1,int a2)
 {
     return dfn[a1]<dfn[a2];
 }
 void dfs(int a1)
 {
     dfn[a1]=++T;
     for(int i=;(<<i)<=deep[a1];i++)
       fa[a1][i]=fa[fa[a1][i-]][i-];
     for(int i=head[a1];i;i=next[i])
       if(fa[a1][]!=u[i])
         {
             deep[u[i]]=deep[a1]+;
             fa[u[i]][]=a1;
             dfs(u[i]);
         }
     return;
 }
 int lca(int a1,int a2)
 {
     if(deep[a1]<deep[a2])
       swap(a1,a2);
     int a3=deep[a1]-deep[a2];
     for(int i=;i<=;i++)
       if(a3&(<<i))
         a1=fa[a1][i];
     for(int i=;i>=;i--)
       if(fa[a1][i]!=fa[a2][i])
         {
             a1=fa[a1][i];
             a2=fa[a2][i];
         }
     if(a1==a2)
       return a1;
     return fa[a1][];
 }
 void dp(int x){
     sum[x]=;
     mx[x]=v[x]?:-inf;
     mn[x]=v[x]?:inf;
     size[x]=v[x];
     for(int i=head1[x];i;i=next1[i]){
         int v=u1[i];
         dp(v);
         cn1+=(sum[x]+size[x]*v1[i])*size[v]+size[x]*sum[v];
         size[x]+=size[v];
         sum[x]+=sum[v]+(ll)size[v]*v1[i];
         mi1=min(mi1,mn[v]+mn[x]+v1[i]);
         mx1=max(mx1,mx[v]+mx[x]+v1[i]);
         mn[x]=min(mn[x],mn[v]+v1[i]);
         mx[x]=max(mx[x],mx[v]+v1[i]);
     }
     head1[x]=;
 }
 void solve(){
     cnt=cn1=;mi1=inf;mx1=-inf;
     int K;
     scanf("%d",&K);
     for(int i=;i<=K;i++) scanf("%d",&h[i]),v[h[i]]=;
     sort(h+,h+K+,cmp);int top=;st[]=;
     for(int i=;i<=K;i++){
         int now=h[i],f=lca(st[top],now);
         if(dfn[f]==dfn[st[top]]) st[++top]=now;
         else{
             while(top){
                 int q=st[top-];
                 if(dfn[q]>dfn[f]) jia2(st[top-],st[top]),top--;
                 else if(dfn[q]==dfn[f]){
                     jia2(q,st[top]);top--;break;
                 }
                 else {
                     jia2(f,st[top]);st[top]=f;break;
                 }
             }
             if(st[top]!=now) st[++top]=now;
         }
     }
     while(--top)jia2(st[top],st[top+]);
     dp();
     printf("%lld ",cn1);
     printf("%d %d\n",mi1,mx1);
     for(int i=;i<=K;i++) v[h[i]]=;
 }
 int main()
 {
     scanf("%d",&n);
     for(int i=;i<n;i++)
       {
         int a1,a2;
         scanf("%d%d",&a1,&a2);
         jia(a1,a2);
         jia(a2,a1);
       }
     dfs();
     scanf("%d",&m);
     for(int i=;i<=m;i++)
       solve();
     return ;
 }

虚树，树形DP