[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：

  1 #pragma comment(linker, "/STACK:10240000,10240000")
  2
  3 #include <iostream>
  4 #include <cstdio>
  5 #include <algorithm>
  6 #include <cstdlib>
  7 #include <cstring>
  8 #include <map>
  9 #include <queue>
 10 #include <deque>
 11 #include <cmath>
 12 #include <vector>
 13 #include <ctime>
 14 #include <cctype>
 15 #include <set>
 16
 17 using namespace std;
 18
 19 #define mem0(a) memset(a, 0, sizeof(a))
 20 #define lson l, m, rt << 1
 21 #define rson m + 1, r, rt << 1 | 1
 22 #define define_m int m = (l + r) >> 1
 23 #define Rep(a, b) for(int a = 0; a < b; a++)
 24 #define lowbit(x) ((x) & (-(x)))
 25 #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) {}
 26 #define constructInt3(name, a, b, c) name(int a = 0, int b = 0, int c = 0): a(a), b(b), c(c) {}
 27 #define constructInt2(name, a, b) name(int a = 0, int b = 0): a(a), b(b) {}
 28
 29 typedef double db;
 30 typedef long long LL;
 31 typedef pair<int, int> pii;
 32 typedef multiset<int> msi;
 33 typedef multiset<int>::iterator msii;
 34 typedef set<int> si;
 35 typedef set<int>::iterator sii;
 36 typedef vector<int> vi;
 37
 38 const int dx[8] = {1, 0, -1, 0, 1, 1, -1, -1};
 39 const int dy[8] = {0, -1, 0, 1, -1, 1, 1, -1};
 40 const int maxn = 1e5 + 7;
 41 const int maxm = 1e5 + 7;
 42 const int maxv = 1e7 + 7;
 43 const int MD = 1e9 +7;
 44 const int INF = 1e9 + 7;
 45 const double PI = acos(-1.0);
 46 const double eps = 1e-10;
 47
 48 template<class edge> struct Graph {
 49     vector<vector<edge> > adj;
 50     Graph(int n) { adj.clear(); adj.resize(n + 5); }
 51     Graph() { adj.clear(); }
 52     void resize(int n) { adj.resize(n + 5); }
 53     void add(int s, edge e){ adj[s].push_back(e); }
 54     void del(int s, edge e) { adj[s].erase(find(iter(adj[s]), e)); }
 55     void clear() { adj.clear(); }
 56     vector<edge>& operator [](int t) { return adj[t]; }
 57 };
 58
 59 template<class T> struct TreeArray {
 60     vector<T> c;
 61     int maxn;
 62     TreeArray(int n) { c.resize(n + 5); maxn = n + 2; }
 63     TreeArray() { c.clear(); maxn = 0; }
 64     void clear() { memset(&c[0], 0, sizeof(T) * maxn); }
 65     void resize(int n) { c.resize(n + 5); maxn = n + 2; }
 66     void add(int p, T x) { while (p <= maxn) { c[p] += x; p += lowbit(p); } }
 67     T get(int p) { T res = 0; while (p) { res += c[p]; p -= lowbit(p); } return res; }
 68     T range(int a, int b) { return get(b) - get(a - 1); }
 69 };
 70
 71 bool cmp(const pair<pii, int> &a, const pair<pii, int> &b) {
 72     return a.first.second < b.first.second;
 73 }
 74
 75 int a[maxn], b[maxn], c, n, k, L[maxn], R[maxn], vis[maxn], cc, out[maxn];
 76
 77 TreeArray<int> ts;
 78 pair<pii, int> in[maxn];
 79 Graph<int> G;
 80
 81 int find(int x) { return lower_bound(b + 1, b + c + 1, x) - b; }
 82
 83 void DFS(int u) {
 84     vis[u] = 1;
 85     L[u] = ++cc;
 86     b[cc] = a[u];
 87     for (int i = 0; i < G[u].size(); i++) {
 88         if (!vis[G[u][i]] || !vis[G[u][i]]) {
 89             DFS(G[u][i]);
 90         }
 91     }
 92     R[u] = cc;
 93 }
 94
 95 int main() {
 96     //freopen("in.txt", "r", stdin);
 97     int T, cas = 0, m;
 98     cin >> T;
 99     while (T--) {
100         scanf("%d%d", &n, &k);
101         for (int i = 1; i <= n; i++) {
102             scanf("%d", a + i);
103         }
104         G.clear();
105         G.resize(n);
106         for (int i = 1, u, v; i < n; i++) {
107             scanf("%d%d", &u, &v);
108             G.add(u, v);
109             G.add(v, u);
110         }
111         mem0(vis);
112         cc = 0;
113         DFS(1);
114         memcpy(a, b, sizeof(b));
115         sort(b + 1, b + n + 1);
116         c = unique(b + 1, b + n + 1) - b - 1;
117         for (int i = 1; i <= n; i++) {
118             a[i] = find(a[i]);
119         }
120         cin >> m;
121         for (int i = 0, x; i < m; i++) {
122             scanf("%d", &x);
123             in[i].first = make_pair(L[x], R[x]);
124             in[i].second = i;
125         }
126         sort(in, in + m, cmp);
127         G.clear();
128         G.resize(n);
129         ts.clear();
130         ts.resize(n);
131         mem0(vis);
132
133         int last = 0;
134         for (int i = 0; i < m; i++) {
135             for (int j = last + 1; j <= in[i].first.second; j++) {
136                 G.add(a[j], j);
137                 int sz = G[a[j]].size();
138                 if (sz >= k) {
139                     ts.add(G[a[j]][sz - k], 1);
140                     if (sz > k) {
141                         ts.add(G[a[j]][sz - k - 1], -2);
142                         if (sz > k + 1) ts.add(G[a[j]][sz - k - 2], 1);
143                     }
144                 }
145             }
146             out[in[i].second] = ts.range(in[i].first.first, in[i].first.second);
147             //cout << out[in[i].second] << " " << in[i].first.first << " " << in[i].first.second << endl;
148
149             last = in[i].first.second;
150         }
151         if (cas) cout << endl;
152         printf("Case #%d:\n", ++cas);
153         for (int i = 0; i < m; i++) {
154             printf("%d\n", out[i]);
155         }
156     }
157     return 0;
158 }