Submission #493140

#	Time	Username	Problem	Language	Result	Execution time	Memory
493140		flappybird	Regions (IOI09_regions)	C++17	60 / 100	8074 ms	131076 KiB

regions

#include <bits/stdc++.h>
#include <unordered_map>
#pragma GCC optimize("O3")
#pragma GCC optimize("Ofast")
#pragma GCC optimize("unroll-loops")
#pragma GCC target("avx,avx2,fma")
using namespace std;
typedef int ll;
typedef pair<ll, ll> pll;
#define MAX 200010
#define MAXS 20
#define INF 1000000000000000001
#define bb ' '
#define ln '\n'
#define Ln '\n'
#define B 200
vector<ll> adj[MAX];
vector<ll> rr[MAX];
pll range[MAX];
ll rrr[MAX];
ll cnt = 0;
ll num[MAX];
vector<vector<ll>> tdp, bdp;
void dfs(ll x, ll p = 0) {
	range[x].first = range[x].second = ++cnt;
	tdp[x] = tdp[p];
	if (num[rrr[x]] != -1) tdp[x][num[rrr[x]]]++, bdp[x][num[rrr[x]]]++;
	for (auto v : adj[x]) {
		if (v == p) continue;
		dfs(v, x);
		range[x].second = max(range[x].second, range[v].second);
		for (ll i = 0; i < bdp[x].size(); i++) bdp[x][i] += bdp[v][i];
	}
}
signed main() {
	ios::sync_with_stdio(false), cin.tie(0);
	ll N, R, Q;
	cin >> N >> R >> Q;
	ll i;
	ll p, r;
	cin >> r;
	rr[r].push_back(1);
	rrr[1] = r;
	for (i = 2; i <= N; i++) {
		cin >> p >> r;
		rrr[i] = r;
		adj[p].push_back(i);
		adj[i].push_back(p);
		rr[r].push_back(i);
	}
	ll nn = 0;
	for (i = 0; i <= R; i++) {
		if (rr[i].size() >= B) num[i] = nn++;
		else num[i] = -1;
	}
	tdp = vector<vector<ll>>(N + 2, vector<ll>(nn));
	bdp = vector<vector<ll>>(N + 2, vector<ll>(nn));
	ll a, b;
	unordered_map<ll, bool> chk;
	unordered_map<ll, long long> val;
	dfs(1);
	for (i = 1; i <= Q; i++) {
		cin >> a >> b;
		if (chk[a * 25001 + b]) cout << val[a * 25001 + b] << endl;
		else {
			long long ans = 0;
			if (rr[a].size() < rr[b].size()) {
				if (num[b] != -1) {
					for (auto x : rr[a]) ans += bdp[x][num[b]];
				}
				else {
					for (auto x : rr[a]) {
						for (auto y : rr[b]) {
							if (range[x].first <= range[y].first && range[y].second <= range[x].second) ans++;
						}
					}
				}
			}
			else {
				if (num[a] != -1) {
					for (auto x : rr[b]) ans += tdp[x][num[a]];
				}
				else {
					for (auto x : rr[a]) {
						for (auto y : rr[b]) {
							if (range[x].first <= range[y].first && range[y].second <= range[x].second) ans++;
						}
					}
				}
			}
			chk[a * 25001 + b] = 1;
			val[a * 25001 + b] = ans;
			cout << ans << endl;
		}
	}
}

Compilation message (stderr)

regions.cpp: In function 'void dfs(ll, ll)':
regions.cpp:32:20: warning: comparison of integer expressions of different signedness: 'll' {aka 'int'} and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   32 |   for (ll i = 0; i < bdp[x].size(); i++) bdp[x][i] += bdp[v][i];
      |                  ~~^~~~~~~~~~~~~~~

• Subtask 1: 15 / 15
• Subtask 2: 45 / 85