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

*/
巴特西

BZOJ2286/Luogu2495 [Sdoi2011]消耗战 (虚树)

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