<虚树+树型DP> HNOI2014世界树

<虚树+树型DP> HNOI2014世界树

#include <iostream>
#include <cstdio>
#include <cstring>
#include <cmath>
#include <algorithm>

using namespace std;

typedef long long LL;
const int MAXN = 3e5 + 10;

inline int in()
{
    int x = 0, flag = 1; char ch = getchar();
    while (ch < '0' || ch > '9') { if (ch == '-') flag = -1; ch = getchar(); }
    while (ch >= '0' && ch <= '9') x = (x << 1) + (x << 3) + (ch ^ 48), ch = getchar();
    return x * flag;
}

int n, m, q;

struct Gra
{
    int head[MAXN], nume;
    struct Adj { int nex, to; } adj[MAXN << 1];
    void clear()
        {
            memset(head, 0, sizeof head);
            nume = 0;
        }
    void addedge(int from, int to)
        {
            adj[++nume] = (Adj) { head[from], to };
            head[from] = nume;
        }
    void link(int from, int to)
        {
            addedge(from, to);
            addedge(to, from);
        }
} g1, g2;

int lg[MAXN], up[20][MAXN], dfn[MAXN], ind, dep[MAXN], size[MAXN];
void DFS(int u)
{
    dfn[u] = ++ind;
    dep[u] = dep[up[0][u]] + 1;
    size[u] = 1;
    for (int i = 1; (1 << i) <= dep[u]; ++ i)
        up[i][u] = up[i - 1][up[i - 1][u]];
    for (int i = g1.head[u]; i; i = g1.adj[i].nex)
    {
        int v = g1.adj[i].to;
        if (v == up[0][u]) continue;
        up[0][v] = u;
        DFS(v);
        size[u] += size[v];
    }
}
int lca(int x, int y)
{
    if (dep[x] > dep[y]) swap(x, y);
    while (dep[x] != dep[y]) y = up[lg[dep[y] - dep[x]]][y];
    if (x == y) return x;
    for (int i = lg[dep[x]]; i >= 0; -- i)
        if (up[i][x] != up[i][y]) x = up[i][x], y = up[i][y];
    return up[0][x];
}

int a[MAXN], id[MAXN], ans[MAXN];
bool cmpd(int x, int y) { return dfn[x] < dfn[y]; }

int stk[MAXN], top;
bool iskey[MAXN];

void insert(int x)
{
    if (x == stk[1]) return;
    int LCA = lca(x, stk[top]);
    if (LCA == stk[top]) return (void)(stk[++top] = x);
    while (top > 1 && dep[LCA] <= dep[stk[top - 1]])
    {
        g2.addedge(stk[top - 1], stk[top]);
        -- top;
    }
    if (LCA != stk[top]) g2.addedge(LCA, stk[top]), stk[top] = LCA;
    stk[++top] = x;
}

struct Mn
{
    int id, v;
} mn[MAXN];
void getmin(int x, int y)
{
    int val = mn[y].v + abs(dep[x] - dep[y]);
    if (val < mn[x].v)
        mn[x] = (Mn) { mn[y].id, val };
    else if (val == mn[x].v && mn[y].id < mn[x].id)
        mn[x].id = mn[y].id;
}
void DFS1(int u)
{
    if (iskey[u]) mn[u] = (Mn) { u, 0 };
    else mn[u] = (Mn) { 300001, 2333333 };
    for (int i = g2.head[u]; i; i = g2.adj[i].nex)
    {
        int v = g2.adj[i].to;
        DFS1(v);
        getmin(u, v);
    }
    return ;
}
int jump(int x, int d)
{
    for (int i = 19; i >= 0; -- i)
        if ((1 << i) <= d) x = up[i][x], d -= (1 << i);
    return x;
}
void DFS2(int u)
{
    ans[mn[u].id] += 1;
    int sum = 0;
    for (int i = g2.head[u]; i; i = g2.adj[i].nex)
    {
        int v = g2.adj[i].to;
        getmin(v, u);
        int dis = dep[v] - dep[u], mid = (mn[u].v + mn[v].v + dis) / 2;
        int uson = jump(v, dis - 1);
        sum += size[uson];
        if (mid - mn[v].v > 0 && mid - mn[v].v < dis)
        {
            int mi = jump(v, mid - mn[v].v), mison = jump(v, mid - mn[v].v - 1);
            ans[mn[v].id] += size[mison] - size[v];
            ans[mn[u].id] += size[uson] - size[mi];
            if (mid * 2 != mn[u].v + mn[v].v + dis) ans[mn[v].id] += size[mi] - size[mison];
            else
            {
                if (mn[u].id < mn[v].id) ans[mn[u].id] += size[mi] - size[mison];
                else ans[mn[v].id] += size[mi] - size[mison];
            }
        }
        else if (mid - mn[v].v <= 0) ans[mn[u].id] += size[uson] - size[v];
        else if (mid - mn[v].v >= dis) ans[mn[v].id] += size[uson] - size[v];
        DFS2(v);
    }
    ans[mn[u].id] += size[u] - sum - 1;
    g2.head[u] = 0;
    iskey[u] = false;
    return ;
}

int main()
{
    g1.clear(); g2.clear();
    n = in();
    for (int i = 1; i <= n; ++ i)
        lg[i] = lg[i - 1] + ((2 << lg[i - 1]) == i);
    for (int i = 1; i < n; ++ i)
    {
        int u = in(), v = in();
        g1.link(u, v);
    }
    DFS(1);
    q = in();
    while (q --)
    {
        m = in();
        g2.nume = 0;
        for (int i = 1; i <= m; ++ i) a[i] = in(), id[i] = a[i];
        sort(a + 1, a + m + 1, cmpd);
        top = 0; stk[++ top] = 1;
        for (int i = 1; i <= m; ++ i) insert(a[i]), iskey[a[i]] = true;
        while (top > 1) g2.addedge(stk[top - 1], stk[top]), -- top;
        DFS1(1);
        DFS2(1);
        for (int i = 1; i <= m; ++ i) printf("%d ", ans[id[i]]); puts("");
        for (int i = 1; i <= m; ++ i) ans[id[i]] = 0;
    }
    return 0;
}