Submission #1046033

#TimeUsernameProblemLanguageResultExecution timeMemory
1046033BuzzyBeezRegions (IOI09_regions)C++17
100 / 100
1944 ms82564 KiB
#pragma GCC optimize("O3,unroll-loops") #include <bits/stdc++.h> using namespace std; vector<int> adj[200008]; int color[200008]; vector<int> occ[25008], occ2[25008]; int tin[200008], tout[200008], euler[200008]; vector<int> ans[25008]; int hrank[25008]; int upd[200008], dp[200008]; void add_edge(int u, int v) {adj[u].push_back(v); adj[v].push_back(u);} int timer = 0; void DFS_EulerTour(int u) { tin[u] = ++timer; euler[timer] = u; for (int v : adj[u]) DFS_EulerTour(v); tout[u] = timer; } int get(int c, int l, int r) { if (l > r) return 0; return upper_bound(occ2[c].begin(), occ2[c].end(), r) - lower_bound(occ2[c].begin(), occ2[c].end(), l); } signed main() { int n, R, q, u, v, r1, r2, res; cin >> n >> R >> q >> color[1]; for (u = 2; u <= n; ++u) cin >> v >> color[u], adj[v].push_back(u); DFS_EulerTour(1); // for (int i = 1; i <= n; ++i) cout << tin[i] << ' ' << tout[i] << '\n'; for (u = 1; u <= n; ++u) occ[color[u]].push_back(u); int S = sqrt(2.0 * n * R / (q * (__lg(n) + 1))); vector<int> heavy; for (int c = 1; c <= R; ++c) if (occ[c].size() > S) heavy.push_back(c), hrank[c] = heavy.size(); for (int c = 1; c <= R; ++c) ans[c].resize(heavy.size() + 1); for (int c : heavy) { for (int u : occ[c]) ++upd[tin[u] + 1], --upd[tout[u] + 1]; for (int i = 1; i <= n; ++i) dp[i] = dp[i - 1] + upd[i]; for (int i = 1; i <= n; ++i) ans[color[euler[i]]][hrank[c]] += dp[i]; for (int u : occ[c]) --upd[tin[u] + 1], ++upd[tout[u] + 1]; for (int i = 1; i <= n; ++i) dp[i] = dp[i - 1] + upd[i]; } for (int c = 1; c <= R; ++c) { for (int u : occ[c]) occ2[c].push_back(tin[u]); sort(occ2[c].begin(), occ2[c].end()); } while (q--) { cin >> r1 >> r2; if (occ[r1].size() > S) cout << ans[r2][hrank[r1]] << endl; else { res = 0; for (int u : occ[r1]) res += get(r2, tin[u] + 1, tout[u]); cout << res << endl; } } }

Compilation message (stderr)

regions.cpp: In function 'int main()':
regions.cpp:34:49: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   34 |  for (int c = 1; c <= R; ++c) if (occ[c].size() > S) heavy.push_back(c), hrank[c] = heavy.size();
      |                                   ~~~~~~~~~~~~~~^~~
regions.cpp:49:22: warning: comparison of integer expressions of different signedness: 'std::vector<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   49 |   if (occ[r1].size() > S) cout << ans[r2][hrank[r1]] << endl;
      |       ~~~~~~~~~~~~~~~^~~
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