Submission #978596

#	Time	Username	Problem	Language	Result	Execution time	Memory
978596		Temmie	Rarest Insects (IOI22_insects)	C++17	100 / 100	1000 ms	16452 KiB

insects

#include "insects.h"

#include <bits/stdc++.h>

std::set <int> IN;

std::set <int> last;

void inside(int x) {
	IN.insert(x);
}

void outside(int x) {
	IN.erase(x);
}

int ask(int n) {
	for (int i = 0; i < n; i++) {
		if (IN.count(i) && !last.count(i)) {
			move_inside(i);
		} else if (!IN.count(i) && last.count(i)) {
			move_outside(i);
		}
	}
	static std::map <std::vector <int>, int> mem;
	last = IN;
	std::vector <int> tmp;
	for (int x : IN) tmp.push_back(x);
	auto it = mem.find(tmp);
	if (it != mem.end()) return it->second;
	return mem[tmp] = press_button();
	// return press_button();
}

std::vector <int> invert(std::vector <int> v, int n) {
	std::vector <int> u;
	std::sort(v.begin(), v.end());
	for (int i = 0, j = 0; i < n; i++) {
		if (j < (int) v.size() && v[j] == i) {
			j++;
			continue;
		}
		u.push_back(i);
	}
	return u;
}

int min_cardinality(int n) {
	std::vector <int> in, pool;
	for (int i = 0; i < n; i++) {
		inside(i);
		in.push_back(i);
		if (ask(n) == 1) continue;
		outside(i);
		in.pop_back();
		pool.push_back(i);
	}
	int uniq = in.size();
	int ans = 1;
	srand(time(0));
	for (int l = 2, r = n / uniq; l <= r; ) {
		int mid = (l + r) >> 1;
		in.clear();
		std::vector <int> new_pool;
		std::random_shuffle(pool.begin(), pool.end());
		for (int i : pool) {
			inside(i);
			in.push_back(i);
			if ((int) IN.size() == uniq * mid + 1 || ask(n) > mid) {
				outside(i);
				in.pop_back();
				new_pool.push_back(i);
				continue;
			}
		}
		pool = new_pool;
		if ((int) IN.size() == uniq * mid) {
			ans = mid;
			l = mid + 1;
		} else {
			r = mid - 1;
			pool = in;
			for (int x : in) {
				outside(x);
			}
		}
	}
	return ans;
}

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