Submission #840606

#	Time	Username	Problem	Language	Result	Execution time	Memory
840606		mat_jur	Regions (IOI09_regions)	C++17	21 / 100	1491 ms	131072 KiB

regions

#include <bits/stdc++.h>
using namespace std;
#ifdef DEBUG
auto&operator<<(auto &o, pair<auto, auto> p) {o << "(" << p.first << ", " << p.second << ")"; return o;}
auto operator<<(auto &o, auto x)->decltype(x.end(), o) {o<<"{"; for(auto e : x) o<<e<<", "; return o<<"}";}
#define debug(X) cerr << "["#X"]: " << X << '\n';
#else 
#define debug(X) ;
#endif
#define ll long long
#define all(v) (v).begin(), (v).end()
#define FOR(i,l,r) for(int i=(l);i<=(r);++i)
#define ROF(i,r,l) for(int i=(r);i>=(l);--i)
#define REP(i,n) FOR(i,0,(n)-1)
#define ssize(x) int(x.size())
#define fi first
#define se second
#define eb emplace_back

int main () {
	ios_base::sync_with_stdio(0);
	cin.tie(0);
	cout.tie(0);

	int n, r, q;
	cin >> n >> r >> q;
	vector<int> h(n);
	vector G(n, vector(0, 0)), wyst(r, vector(0, 0));
	cin >> h[0];
	h[0]--;
	FOR(i, 1, n-1) {
		int p;
		cin >> p >> h[i];
		p--;
		h[i]--;
		G[p].eb(i);
		G[i].eb(p);
	}
	const int B = (int(sqrt(r))); 
	vector<int> big, bigIdx(n, -1);
	vector<int> start(n), end(n), s(n);
	int timer = 0;
	function<void(int, int)> dfs2 = [&](int v, int p) {
		start[v] = timer++;
		s[v] = 1;
		for(auto w : G[v]) {
			if (w == p) continue;
			dfs2(w, v);
			s[v] += s[w];
		}
		end[v] = timer-1;
	};
	dfs2(0, -1);
	REP(i, n) wyst[h[i]].eb(start[i]);

	REP(i, r) {
		if (ssize(wyst[i]) > B) {big.eb(i); bigIdx[i] = ssize(big)-1;}
	}
	auto merge = [&](vector<int> &a, vector<int> &b) {
		REP(i, ssize(big)) a[i] += b[i];
		return;
	};
	vector ans(r, vector(ssize(big), 0ll));
	function<vector<int>(int, int)> dfs = [&](int v, int p) {
		vector<int> cnt(ssize(big));
		for(auto w : G[v]) {
			if (w == p) continue;
			vector<int> b = dfs(w, v);
			merge(cnt, b);
		}
		REP(i, ssize(big)) ans[h[v]][i] += cnt[i];
		if(bigIdx[h[v]] >= 0) cnt[bigIdx[h[v]]]++;
		return cnt;
	};
	dfs(0, -1);

	REP(j, q) {
		int r1, r2;
		cin >> r1 >> r2;
		r1--; r2--;
		if (bigIdx[r2] >= 0) {
//			cerr << "CASE 1 \n";
			cout << ans[r1][bigIdx[r2]] << '\n';
			cout.flush();
			continue;
		}
		ll res = 0;
		for (auto v : wyst[r2]) {
			auto up = upper_bound(all(wyst[r1]), end[v])-1, low = lower_bound(all(wyst[r1]), start[v]);
			res += up-low+1;
		}
		cout << res << '\n';
		cout.flush();
	}

	return 0;
}

• Subtask 1: 6 / 15
• Subtask 2: 15 / 85