BZOJ2286/Luogu2495 [Sdoi2011]消耗战 (虚树)

// never forget open "Head.cpp", boy, never !
#include <iostream>
#include <cstdio>
#include <cstring>
#include <algorithm>
#include <cmath>
#define R(a,b,c) for(register int  a = (b); a <= (c); ++ a)
#define nR(a,b,c) for(register int  a = (b); a >= (c); -- a)
#define Max(a,b) ((a) > (b) ? (a) : (b))
#define Min(a,b) ((a) < (b) ? (a) : (b))
#define Fill(a,b) memset(a, b, sizeof(a))
#define Swap(a,b) a^=b^=a^=b
#define ll long long
#define ON_DEBUG

#ifdef ON_DEBUG

#define D_e_Line printf("\n\n----------\n\n")
#define D_e(x)  cout << #x << " = " << x << endl
#define Pause() system("pause")

#else

#define D_e_Line ;

#endif

struct ios{
    template<typename ATP>ios& operator >> (ATP &x){
        x = 0; int f = 1; char c;
        for(c = getchar(); c < '0' || c > '9'; c = getchar()) if(c == '-')  f = -1;
        while(c >= '0' && c <= '9') x = x * 10 + (c ^ '0'), c = getchar();
        x*= f;
        return *this;
    }
}io;
using namespace std;
#include <vector>

const int N = 250007;

int n;

namespace EdgeStar{

struct Edge{
    int nxt, pre, w;
}e[N << 1];
int head[N], cntEdge;
inline void add(int u, int v, int w){
    e[++cntEdge] = (Edge){head[u], v, w}, head[u] = cntEdge;
}

}
using namespace EdgeStar;

long long minn[N];

namespace TreeChainParticipation{

int siz[N], son[N], fa[N], dep[N];
inline void DFS_First(int u, int father){
    fa[u] = father, dep[u] = dep[father] + 1, siz[u] = 1;
    for(register int i = head[u]; i; i = e[i].nxt){
        int v = e[i].pre;
        if(v == father) continue;
        minn[v] = Min(minn[u], e[i].w);
        DFS_First(v, u);

        siz[u] += siz[v];
        if(!son[u] || siz[v] > siz[son[u]]){
            son[u] = v;
        }
    }

}
int top[N], dfn[N], dfnIdx;
inline void DFS_Second(int u, int ancester){
    top[u] = ancester, dfn[u] = ++dfnIdx;
    if(!son[u]) return;
    DFS_Second(son[u], ancester);
    for(register int i = head[u]; i; i = e[i].nxt){
        int v = e[i].pre;
        if(v != fa[u] && v != son[u]){
            DFS_Second(v, v);
        }
    }
}
inline int LCA(int x, int y){
    while(top[x] != top[y]){
        if(dep[top[x]] < dep[top[y]]) Swap(x, y);
        x = fa[top[x]];
    }
    return dep[x] < dep[y] ? x : y;
}

}
using namespace TreeChainParticipation;

int sta[N], _top;
vector<int> G[N];

//Vitual Tree
inline void Insert(int x){
    if(_top == 1){
        sta[++_top] = x;
        return;
    }
    int lca = LCA(x, sta[_top]);
    if(lca == sta[_top]){
    	//G[sta[_top]].push_back(x);
    	//sta[++_top] = x;
    	return;
    }
    while(_top > 1 && dfn[sta[_top - 1]] >= dfn[lca]){
        G[sta[_top - 1]].push_back(sta[_top]);
        --_top;
    }
    // maybe it's not need in this problem // or maybe need ? // shit, of course ! Who said the node 1 should be root
    if(lca != sta[_top]){
        G[lca].push_back(sta[_top]);
        sta[_top] = lca;
    }
    sta[++_top] = x;
}

inline long long DFS(int u){
    if(G[u].size() == 0) return minn[u];
    long long sum = 0;
    for(vector<int>::iterator v = G[u].begin(); v != G[u].end(); ++v){
        sum += DFS(*v);
    }
    G[u].clear();
    return Min(sum, minn[u]);
}

int act[N];

inline int cmp(const int &a, const int &b){
    return dfn[a] < dfn[b];
}

int main(){

    io >> n;
    R(i,2,n){
        int u, v, w;
        io >> u >> v >> w;
        add(u, v, w);
        add(v, u, w);
    }

    minn[1] = 9223372036854775807;

    DFS_First(1, 0);
    DFS_Second(1, 1);

    int Tasks;
    io >> Tasks;
    while(Tasks--){
        int m;
        io >> m;
        R(i,1,m){
            io >> act[i];
        }
        sort(act + 1, act + m + 1, cmp); // important !
        _top = 1;
        sta[_top] = 1;
        R(i,1,m){
             Insert(act[i]);
        }
        while(_top){
            G[sta[_top - 1]].push_back(sta[_top]);
            --_top;
        }

        printf("%lld\n", DFS(1));
    }

    return 0;
}

/*
10
1 5 13
1 9 6
2 1 19
2 4 8
2 3 91
5 6 8
7 5 4
7 8 31
10 7 9
3
2 10 6
4 5 7 8 3
3 9 4 6

*/