Submission #911137

#	Time	Username	Problem	Language	Result	Execution time	Memory
911137		MinaRagy06	Inside information (BOI21_servers)	C++17	70 / 100	3536 ms	90416 KiB

servers

#include <bits/stdc++.h>
#pragma GCC optimize("Ofast")
using namespace std;
typedef int64_t ll;
#define SZ(x) (int) x.size()

const int N = 120'005, LOG = 18, B = 700;
vector<array<int, 3>> adj[N];
//0: increasing, 1: decreasing, {ancestor, last weight}
array<int, 3> bl[N][LOG][2];
int st[N], en[N], curt;
void dfs(int i, int par, int part) {
	bl[i][0][0] = {par, part, part};
	bl[i][0][1] = {par, part, part};
	for (int j = 1; j < LOG; j++) {
		{
			bl[i][j][0] = bl[i][j - 1][0];
			auto [lst, lstt, mx] = bl[i][j][0];
			if (lstt <= bl[lst][0][0][1]) {
				bl[i][j][0] = bl[lst][j - 1][0];
				bl[i][j][0][2] = max(bl[i][j][0][2], mx);
			}
		}
		{
			bl[i][j][1] = bl[i][j - 1][1];
			auto [lst, lstt, mx] = bl[i][j][1];
			if (lstt >= bl[lst][0][1][1]) {
				bl[i][j][1] = bl[lst][j - 1][1];
				bl[i][j][1][2] = max(bl[i][j][1][2], mx);
			}
		}
	}
	st[i] = curt++;
	for (auto [nxt, t, nxtidx] : adj[i]) {
		if (nxt == par) continue;
		dfs(nxt, i, t);
	}
	en[i] = curt;
}
bool isanc(int l, int b) {
	if (st[l] <= st[b] && en[b] <= en[l]) {
		return 1;
	}
	return 0;
}
array<int, 2> check(int t, int a, int b) {
	int mx = -1e9, high = bl[a][LOG - 1][t][0];
	if (!isanc(high, b)) {
		return {int(1e9), 0};
	}
	if (a == high || isanc(a, b)) {
		return {int(-1e9), (t == 1? 1 : -1) * int(1e9)};
	}
	for (int j = LOG - 1; j >= 0; j--) {
		if (!isanc(bl[a][j][t][0], b)) {
			mx = max(mx, bl[a][j][t][2]);
			a = bl[a][j][t][0];
		}
	}
	return {max(mx, bl[a][0][t][2]), bl[a][0][t][1]};
}
vector<int> dp[N];
int lst;
int solve(int i, int par) {
	if (~dp[i][par]) return dp[i][par];
	int j = (par == SZ(adj[i])? 0 : par + 1);
	dp[i][par] = 1;
	if (j < SZ(adj[i])) {
		if (adj[i][j][1] > lst) return dp[i][par];
		dp[i][par] += solve(adj[i][j][0], adj[i][j][2]) + solve(i, j) - 1;
	}
	return dp[i][par];
}
bool checkpath(int a, int b, int t, bool x) {
	array<int, 2> l = check(x, a, b), r = check(!x, b, a);
	if (l[0] <= t && r[0] <= t && (l[1] == r[1] || (x ^ (l[1] < r[1]))) ) {
		return 1;
	} else {
		return 0;
	}
}
int main() {
	ios_base::sync_with_stdio(0), cin.tie(0);
	auto S = chrono::steady_clock::now().time_since_epoch().count();
	int n, q;
	cin >> n >> q;
	q += n - 1;
	pair<char, vector<int>> v[q];
	for (int i = 0; i < q; i++) {
		cin >> v[i].first;
		if (v[i].first == 'S') {
			int a, b;
			cin >> a >> b;
			int x = adj[b].size(), y = adj[a].size();
			adj[a].push_back({b, i, x});
			adj[b].push_back({a, i, y});
			v[i].second = {a, b};
		} else if (v[i].first == 'Q') {
			int a, b;
			cin >> a >> b;
			v[i].second = {a, b};
		} else {
			int a;
			cin >> a;
			v[i].second = {a};
		}
	}
	dfs(1, 1, 0);
	for (int i = 1; i <= n; i++) {
		dp[i].resize(adj[i].size() + 1);
		for (int j = 0; j <= SZ(adj[i]); j++) {
			dp[i][j] = -1;
		}
	}
	vector<array<int, 3>> upd;
	lst = -1;
	ll s = 0;
	for (int i = 0; i < q; i++) {
		if (upd.size() == B) {
			lst = i - 1;
			upd.clear();
			for (int j = 1; j <= n; j++) {
				for (int k = 0; k <= SZ(adj[j]); k++) {
					dp[j][k] = -1;
				}
			}
		}
		if (v[i].first == 'S') {
			int a = v[i].second[0], b = v[i].second[1];
			if (isanc(b, a)) swap(a, b);
			upd.push_back({a, b, i});
		} else if (v[i].first == 'Q') {
			int a = v[i].second[0], b = v[i].second[1];
#ifdef MINA
			s += (checkpath(a, b, i, 1));
#else
			cout << (checkpath(a, b, i, 1)? "yes\n" : "no\n");
#endif
		} else {
			int x = v[i].second[0];
			int ans = solve(x, adj[x].size());
			for (auto [a, b, t] : upd) {
				if (isanc(b, x)) {
					array<int, 2> val = check(0, x, b);
					ans += val[0] <= t - 1;
				} else if (isanc(a, x)) {
					array<int, 2> val = check(0, x, a);
					ans += val[0] <= t - 1;
				} else {
					ans += checkpath(x, a, t - 1, 0);
				}
			}
#ifdef MINA
			s += ans;
#else
			cout << ans << '\n';
#endif
		}
	}
#ifdef MINA
	cout << s << '\n';
	auto E = chrono::steady_clock::now().time_since_epoch().count();
	cout << (E - S) / 1e9 << "s\n";
#endif
	return 0;
}

Compilation message (stderr)

servers.cpp: In function 'int main()':
servers.cpp:84:7: warning: unused variable 'S' [-Wunused-variable]
   84 |  auto S = chrono::steady_clock::now().time_since_epoch().count();
      |       ^
servers.cpp:117:5: warning: unused variable 's' [-Wunused-variable]
  117 |  ll s = 0;
      |     ^

• Subtask 1: 2.5 / 2.5
• Subtask 2: 2.5 / 2.5
• Subtask 3: 2.5 / 2.5
• Subtask 4: 2.5 / 2.5
• Subtask 5: 5 / 5
• Subtask 6: 5 / 5
• Subtask 7: 10 / 10
• Subtask 8: 10 / 10
• Subtask 9: 12.5 / 12.5
• Subtask 10: 0 / 12.5
• Subtask 11: 17.5 / 17.5
• Subtask 12: 0 / 17.5