Submission #1078970

#	Time	Username	Problem	Language	Result	Execution time	Memory
1078970		Gromp15	Rarest Insects (IOI22_insects)	C++17	70 / 100	89 ms	944 KiB

insects

#include <bits/stdc++.h>
#define sz(x) (int)x.size()
#define all(x) x.begin(), x.end()
#include "insects.h"
using namespace std;
template<typename T> bool ckmin(T &a, const T &b) { return a > b ? a = b, 1 : 0; }
template<typename T> bool ckmax(T &a, const T &b) { return a < b ? a = b, 1 : 0; }

int min_cardinality(int N) {
	vector<int> idx(N);
	iota(all(idx), 0);
	shuffle(all(idx), mt19937(1498371));
	vector<int> groups{idx[0]};
	move_inside(idx[0]);
	for (int i = 1; i < N; i++) {
		move_inside(idx[i]);
		if (press_button() > 1) move_outside(idx[i]);
		else groups.push_back(idx[i]);
	}
	for (int x : groups) move_outside(x);
	int ans = 1e9;
	auto solve = [&](auto&& s, vector<int> v, vector<int> pot) -> void {
		if (sz(v) == 1) {
			ckmin(ans, sz(pot)); return;
		}
		if (sz(v) * sz(v) < sz(pot) * 0.5) {
			vector<int> hf(v.begin(), v.begin() + sz(v) / 2), other(v.begin() + sz(v) / 2, v.end());
			for (int x : hf) move_inside(x);
			vector<int> A, B;
			for (int x : pot) {
				if (find(all(hf), x) != hf.end()) A.emplace_back(x);
				else {
					move_inside(x);
					if (press_button() > 1) {
						A.emplace_back(x);
					}
					else {
						B.emplace_back(x);
					}
					move_outside(x);
				}
			}
			for (int x : hf) move_outside(x);
			s(s, hf, A);
			s(s, other, B);
			return;
		}
		int l = 2, r = sz(pot) / sz(v), ans2 = 1;
		while (l <= r) {
			int mid = (l+r)/2;
			vector<int> got;
			for (int x : pot) {
				move_inside(x);
				if (press_button() > mid) move_outside(x);
				else got.push_back(x);
			}
			if (sz(got) == mid * sz(v)) ans2 = mid, l = mid+1;
			else r = mid-1;
			for (int x : got) move_outside(x);
		}
		ckmin(ans, ans2);
	};
	solve(solve, groups, idx);
	return ans;
}

• Subtask 1: 10 / 10
• Subtask 2: 15 / 15
• Subtask 3: 45 / 75