[SDOI2011]消耗战

 这个版本是强行加了  1  节点进去的版本。

坑点：1.初始化不能初始化n个，得初始化k个，否则会T

           2.虚树建边时建有向边比较好

#include <bits/stdc++.h>
using namespace std;
typedef long long LL;
typedef LL lint;
const lint maxn = 300001;
const lint maxm = 600001;
const lint inf = 0x3f3f3f3f;
lint tot,he[maxn],ver[maxm],ne[maxm],cost[maxm];
void add( lint x,lint y,lint w ){
    ver[++tot]=y;
    ne[tot]=he[x];
    he[x]=tot;
    cost[tot]=w;
}
lint tot2,he2[maxn],ver2[maxm],ne2[maxm],cost2[maxm];
void add2( lint x,lint y,lint w ){
    ver2[++tot2]=y;
    ne2[tot2]=he2[x];
    he2[x]=tot2;
    cost2[tot2]=w;
}
lint vis[maxn];
void init(lint n){
    for(lint i = 1;i<= n;i++) he2[i]=0,vis[i]=0;
    tot2=1;
}
lint d[maxn],f[maxn][21],dfn[maxn],cnt = 0,f2[maxn][21];
queue<lint> que;
void dfs( lint x ,lint fa ){
    dfn[x]=++cnt;
    for( lint cure = he[x];cure;cure = ne[cure] ){
        lint y = ver[cure];
        if( y == fa ) continue;
        f[y][0]=x;f2[y][0]=cost[cure];
        d[y]=d[x]+1;
        for( lint i = 1; (1<< i)<=d[y];i++ ){
            f[y][i]=f[ f[y][i-1] ][i-1];
            f2[y][i] = min( f2[y][i-1],f2[ f[y][i-1] ][i-1] );
        }
        dfs(y,x);
    }
}
lint lca( lint x,lint y ){
    if( d[x]<d[y] ) swap(x,y);
    for( lint i = 20;i>=0;i-- ){
        if(  f[x][i] &&d[f[x][i]] >= d[y] ) x=f[x][i];
    }
    if(x==y) return x;
    for( lint i = 20;i>=0;i-- ){
        if( f[x][i]==f[y][i] ) continue;
        x=f[x][i];y=f[y][i];
    }
    return f[x][0];
}
lint lca2( lint x,lint y ){
    if( d[x]<d[y] ) swap(x,y);
    lint res = inf;
    for( lint i = 20;i>=0;i-- ){
        if( f[x][i] && d[ f[x][i] ] >= d[y] ) {
            res = min( res,f2[x][i] );
            x = f[x][i];
        }
    }
    return res;
}
bool cmp( lint x,lint y ){
    return dfn[x]<dfn[y];
}
vector<lint> ve;
lint st[maxn],top;
LL dp( lint x,lint fa ){
    LL res = 0;
    bool flag = false;
    for( lint cure = he2[x];cure;cure = ne2[cure] ){
        lint y = ver2[cure];
        flag = true;
        lint cur = dp(y,x);
        if(!vis[y]) res += min( (LL)cost2[cure],cur  );
        else res += cost2[cure];
    }
    he2[x]=0;
    if(flag)return res;
    return inf;
}
lint solve(){
    top=0;
    sort(ve.begin(),ve.end(),cmp);
    if( ve[0] != 1 ) st[++top]=1;
    for( lint i=0;i< ve.size();i++ ){
        if(ve[i]==1)continue;
        if(!top)st[++top]=ve[i];
        else{
            lint anc=lca(st[top],ve[i]);
            while(top && d[anc] < d[st[top]]){
                if(  top == 1 || d[st[top-1]] < d[anc] ){
                    //add2( st[top],anc,lca2(st[top],anc) );
                    add2( anc,st[top],lca2( st[top],anc ) );
                    st[top]=anc;
                    break;
                }
                //add2( st[top],st[top-1],lca2(st[top],st[top-1]) );
                add2( st[top-1],st[top],lca2(st[top],st[top-1]) );
                top--;
            }
            st[++top]=ve[i];
        }
    }
    while( top>1 ){
        //add2( st[top],st[top-1],lca2(st[top],st[top-1]) );
        add2( st[top-1],st[top],lca2(st[top],st[top-1]) );
        top--;
    }
    return dp(1,0);
}
int main(){
    lint n;
    tot=1;
    scanf("%lld",&n);
    for( lint i = 1;i <= n-1;i++ ){
        lint x,y,w;
        scanf("%lld%lld%lld",&x,&y,&w);
        add(x,y,w);add(y,x,w);
    }
    dfs(1,0);
    lint m;
    scanf("%lld",&m);
    for( lint k,d,i = 1;i <=m;i++ ){
        scanf("%lld",&k);
        ve.clear();tot2 = 1;
        for( lint j = 1;j<=k;j++ ){
            scanf("%lld",&d);vis[d]=1;
            ve.push_back(d);
        }
        LL ans= solve();
        for( lint i = 0;i < ve.size();i++ ) vis[ve[i]]=0;
        printf("%lld\n",ans);
    }
    return 0;
}

 这是一个大佬写的不含1节点的版本

#include<iostream>
#include<cstdio>
#include<cstdlib>
#include<cmath>
#include<cstring>
#include<algorithm>
#define F(i,j,n) for(int i=j;i<=n;i++)
#define D(i,j,n) for(int i=j;i>=n;i--)
#define ll long long
#define maxn 250005
#define inf 1000000000000000000ll
using namespace std;
int n,m,k,cnt,tot,top;
int head[maxn],head2[maxn],d[maxn],pos[maxn],p[maxn][25],a[maxn],s[maxn];
bool tag[maxn];
ll f[maxn],mn[maxn];
struct edge_type{int next,to,v;}e[maxn*2];
struct edge_type2{int next,to;}e2[maxn];
inline int read()
{
    int x=0,f=1;char ch=getchar();
    while (ch<'0'||ch>'9'){if (ch=='-') f=-1;ch=getchar();}
    while (ch>='0'&&ch<='9'){x=x*10+ch-'0';ch=getchar();}
    return x*f;
}
inline void add_edge(int x,int y,int z)
{
    e[++cnt]=(edge_type){head[x],y,z};head[x]=cnt;
    e[++cnt]=(edge_type){head[y],x,z};head[y]=cnt;
}
inline void add_edge2(int x,int y)
{
    e2[++cnt]=(edge_type2){head2[x],y};head2[x]=cnt;
}
inline bool cmp(int x,int y)
{
    return pos[x]<pos[y];
}
inline void dfs(int x,int fa)
{
    pos[x]=++tot;
    for(int i=1;(1<<i)<=d[x];i++) p[x][i]=p[p[x][i-1]][i-1];
    for(int i=head[x];i;i=e[i].next) if (e[i].to!=fa)
    {
        mn[e[i].to]=min(mn[x],(ll)e[i].v);
        d[e[i].to]=d[x]+1;
        p[e[i].to][0]=x;
        dfs(e[i].to,x);
    }
}
inline int lca(int x,int y)
{
    if (d[x]<d[y]) swap(x,y);
    int t=d[x]-d[y];
    for(int i=0;(1<<i)<=t;i++) if (t&(1<<i)) x=p[x][i];
    if (x==y) return x;
    D(i,20,0) if (p[x][i]!=p[y][i]) x=p[x][i],y=p[y][i];
    return p[x][0];
}
inline void dp(int x)
{
    f[x]=mn[x];
    ll tmp=0;
    for(int i=head2[x];i;i=e2[i].next) dp(e2[i].to),tmp+=f[e2[i].to];
    if (tmp&&!tag[x]) f[x]=min(f[x],tmp);
    head2[x]=0;
}
inline void solve()
{
    cnt=0;
    k=read();
    F(i,1,k) a[i]=read(),tag[a[i]]=true;
    sort(a+1,a+k+1,cmp);
    top=0;
    F(i,1,k)
    {
        if (top==0){s[++top]=a[i];continue;}
        int lc=lca(s[top],a[i]);
        while (d[lc]<d[s[top]])
        {
            if (d[lc]>=d[s[top-1]])
            {
                add_edge2(lc,s[top]);
                if (s[--top]!=lc) s[++top]=lc;
                break;
            }
            add_edge2(s[top-1],s[top]);top--;
        }
        s[++top]=a[i];
    }
    while (top>1) add_edge2(s[top-1],s[top]),top--;
    dp(s[1]);printf("%lld\n",f[s[1]]);
    for (int i=1;i<=k;i++) tag[a[i]]=false;
}
int main()
{
    n=read();
    F(i,1,n-1)
    {
        int x=read(),y=read(),z=read();
        add_edge(x,y,z);
    }
    mn[1]=inf;dfs(1,0);
    m=read();
    while (m--) solve();
    return 0;
}