[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 }

View Code