[hdu4358]树状数组

思路：用一个数组记录最近k次的出现位置，然后在其附近更新答案。具体见代码：

#pragma comment(linker, "/STACK:10240000,10240000")

#include <iostream>
#include <cstdio>
#include <algorithm>
#include <cstdlib>
#include <cstring>
#include <map>
#include <queue>
#include <deque>
#include <cmath>
#include <vector>
#include <ctime>
#include <cctype>
#include <set>

using namespace std;

#define mem0(a) memset(a, 0, sizeof(a))
#define lson l, m, rt << 1
#define rson m + 1, r, rt << 1 | 1
#define define_m int m = (l + r) >> 1
#define Rep(a, b) for(int a = 0; a < b; a++)
#define lowbit(x) ((x) & (-(x)))
#define constructInt4(name, a, b, c, d) name(int a = 0, int b = 0, int c = 0, int d = 0): a(a), b(b), c(c), d(d) {}
#define constructInt3(name, a, b, c) name(int a = 0, int b = 0, int c = 0): a(a), b(b), c(c) {}
#define constructInt2(name, a, b) name(int a = 0, int b = 0): a(a), b(b) {}

typedef double db;
typedef long long LL;
typedef pair<int, int> pii;
typedef multiset<int> msi;
typedef multiset<int>::iterator msii;
typedef set<int> si;
typedef set<int>::iterator sii;
typedef vector<int> vi;

const int dx[8] = {1, 0, -1, 0, 1, 1, -1, -1};
const int dy[8] = {0, -1, 0, 1, -1, 1, 1, -1};
const int maxn = 1e5 + 7;
const int maxm = 1e5 + 7;
const int maxv = 1e7 + 7;
const int MD = 1e9 +7;
const int INF = 1e9 + 7;
const double PI = acos(-1.0);
const double eps = 1e-10;

template<class edge> struct Graph {
    vector<vector<edge> > adj;
    Graph(int n) { adj.clear(); adj.resize(n + 5); }
    Graph() { adj.clear(); }
    void resize(int n) { adj.resize(n + 5); }
    void add(int s, edge e){ adj[s].push_back(e); }
    void del(int s, edge e) { adj[s].erase(find(iter(adj[s]), e)); }
    void clear() { adj.clear(); }
    vector<edge>& operator [](int t) { return adj[t]; }
};

template<class T> struct TreeArray {
    vector<T> c;
    int maxn;
    TreeArray(int n) { c.resize(n + 5); maxn = n + 2; }
    TreeArray() { c.clear(); maxn = 0; }
    void clear() { memset(&c[0], 0, sizeof(T) * maxn); }
    void resize(int n) { c.resize(n + 5); maxn = n + 2; }
    void add(int p, T x) { while (p <= maxn) { c[p] += x; p += lowbit(p); } }
    T get(int p) { T res = 0; while (p) { res += c[p]; p -= lowbit(p); } return res; }
    T range(int a, int b) { return get(b) - get(a - 1); }
};

bool cmp(const pair<pii, int> &a, const pair<pii, int> &b) {
    return a.first.second < b.first.second;
}

int a[maxn], b[maxn], c, n, k, L[maxn], R[maxn], vis[maxn], cc, out[maxn];

TreeArray<int> ts;
pair<pii, int> in[maxn];
Graph<int> G;

int find(int x) { return lower_bound(b + 1, b + c + 1, x) - b; }

void DFS(int u) {
    vis[u] = 1;
    L[u] = ++cc;
    b[cc] = a[u];
    for (int i = 0; i < G[u].size(); i++) {
        if (!vis[G[u][i]] || !vis[G[u][i]]) {
            DFS(G[u][i]);
        }
    }
    R[u] = cc;
}

int main() {
    //freopen("in.txt", "r", stdin);
    int T, cas = 0, m;
    cin >> T;
    while (T--) {
        scanf("%d%d", &n, &k);
        for (int i = 1; i <= n; i++) {
            scanf("%d", a + i);
        }
        G.clear();
        G.resize(n);
        for (int i = 1, u, v; i < n; i++) {
            scanf("%d%d", &u, &v);
            G.add(u, v);
            G.add(v, u);
        }
        mem0(vis);
        cc = 0;
        DFS(1);
        memcpy(a, b, sizeof(b));
        sort(b + 1, b + n + 1);
        c = unique(b + 1, b + n + 1) - b - 1;
        for (int i = 1; i <= n; i++) {
            a[i] = find(a[i]);
        }
        cin >> m;
        for (int i = 0, x; i < m; i++) {
            scanf("%d", &x);
            in[i].first = make_pair(L[x], R[x]);
            in[i].second = i;
        }
        sort(in, in + m, cmp);
        G.clear();
        G.resize(n);
        ts.clear();
        ts.resize(n);
        mem0(vis);

        int last = 0;
        for (int i = 0; i < m; i++) {
            for (int j = last + 1; j <= in[i].first.second; j++) {
                G.add(a[j], j);
                int sz = G[a[j]].size();
                if (sz >= k) {
                    ts.add(G[a[j]][sz - k], 1);
                    if (sz > k) {
                        ts.add(G[a[j]][sz - k - 1], -2);
                        if (sz > k + 1) ts.add(G[a[j]][sz - k - 2], 1);
                    }
                }
            }
            out[in[i].second] = ts.range(in[i].first.first, in[i].first.second);
            //cout << out[in[i].second] << " " << in[i].first.first << " " << in[i].first.second << endl;

            last = in[i].first.second;
        }
        if (cas) cout << endl;
        printf("Case #%d:
", ++cas);
        for (int i = 0; i < m; i++) {
            printf("%d
", out[i]);
        }
    }
    return 0;
}