제출 #895441

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
895441		MinaRagy06	Regions (IOI09_regions)	C++17	100 / 100	3688 ms	46600 KiB

regions

#include <bits/stdc++.h>
using namespace std;
#define ll long long

const int N = 200'005, inf = 1e9 + 5;
vector<int> adj[N];
int a[N], p[N], sz[N], order[N], idx[N];
vector<int> above[N], below[N], gud[N];
void calc1(int i, int c, int r) {
	above[r][a[i]] += c;
	above[r][a[i]] = min(above[r][a[i]], inf);
	c += a[i] == order[r];
	for (auto nxt : adj[i]) {
		calc1(nxt, c, r);
	}
}
int calc2(int i, int r) {
	int c = 0;
	for (auto nxt : adj[i]) {
		c += calc2(nxt, r);
	}
	below[r][a[i]] += c;
	below[r][a[i]] = min(below[r][a[i]], inf);
	return c + (a[i] == order[r]);
}
int st[N], en[N], t;
void dfs(int i) {
	st[i] = t++;
	for (auto nxt : adj[i]) {
		dfs(nxt);
	}
	en[i] = t - 1;
}
int main() {
	ios_base::sync_with_stdio(0), cin.tie(0);
	memset(idx, -1, sizeof idx);
	int n, r, q;
	cin >> n >> r >> q;
	cin >> a[0];
	a[0]--;
	for (int i = 1; i < n; i++) {
		cin >> p[i] >> a[i];
		p[i]--;
		a[i]--;
		adj[p[i]].push_back(i);
	}
	for (int i = 0; i < n; i++) {
		sz[a[i]]++;
		gud[a[i]].push_back(i);
	}
	for (int i = 0; i < r; i++) {
		order[i] = i;
	}
	sort(order, order + r, [&](int x, int y) {
		return sz[x] > sz[y];
			});
	int ttl = 0, ttl2 = 0;
	for (int i = 0; i < r; i++) {
		if (!(ttl + r < int(7e5) && ttl2 + n + r < int(1e8))) {
			break;
		}
		idx[order[i]] = i;
		above[i].resize(r);
		below[i].resize(r);
		ttl += r;
		ttl2 += n + r;
		calc1(0, 0, i);
		calc2(0, i);
	}
	dfs(0);
	for (int i = 0; i < r; i++) {
		sort(gud[i].begin(), gud[i].end(), [&] (int x, int y) {
			return st[x] < st[y];
				});
	}
	while (q--) {
		int r1, r2;
		cin >> r1 >> r2;
		r1--, r2--;
		if (~idx[r1]) {
			cout << above[idx[r1]][r2] << endl;
		} else if (~idx[r2]) {
			cout << below[idx[r2]][r1] << endl;
		} else {
			int m = gud[r2].size();
			int bit[m]{};
			auto upd = [&] (int x, int v) {
				for (int i = x; i < m; i = (i | (i + 1))) {
					bit[i] += v;
				}
			};
			auto get = [&] (int x) {
				int ret = 0;
				for (int i = x; i >= 0; i = (i & (i + 1)) - 1) {
					ret += bit[i];
				}
				return ret;
			};
			vector<int> cur = gud[r2];
			for (auto &x : cur) {
				x = st[x];
			}
			for (auto x : gud[r1]) {
				int s = lower_bound(cur.begin(), cur.end(), st[x]) - cur.begin();
				int e = upper_bound(cur.begin(), cur.end(), en[x]) - cur.begin() - 1;
				if (s <= e) {
					upd(s, 1);
					if (e + 1 < m) {
						upd(e + 1, -1);
					}
				}
			}
			int ans = 0;
			for (int i = 0; i < m; i++) {
				ans += get(i);
			}
			cout << ans << endl;
		}
	}
	return 0;
}

• Subtask 1: 15 / 15
• Subtask 2: 85 / 85