Submission #1025323

#	Time	Username	Problem	Language	Result	Execution time	Memory
1025323		Issa	Rarest Insects (IOI22_insects)	C++17	100 / 100	33 ms	596 KiB

insects

#include <bits/stdc++.h>
using namespace std;
typedef long long ll;
pair<int, int> pii;

const int maxn = 1e5 + 100;

int n, d, sz;
int used[maxn];
int f[maxn];
int p[maxn];

void move_inside(int i);
void move_outside(int i);
int press_button();

void add(int i){
	sz++;
	used[i] = 1;
	move_inside(i);
}
void del(int i){
	sz--;
	used[i] = 0;
	move_outside(i);
}
void clear(){
	for(int i = 1; i <= n; i++){
		if(used[i]) del(i);
	}
}

bool ok(int k){
	bool res = 0;
	for(int i = 0; i < n; i++){
		if(used[p[i]]) continue;
		add(p[i]);
		if(press_button() > k){
			del(p[i]);
		} else{
			if(sz >= d * k){
				res = 1;
				break;
			}
		}
	}
	if(res){
		for(int i = 0; i < n; i++){
			if(used[p[i]]) used[p[i]] = 2;
		}
	} else{
		for(int i = 0; i < n; i++){
			if(used[p[i]] == 1){
				del(p[i]);
			} else if(used[p[i]] == 0){
				used[p[i]] = 2;
			}
		}
	}
	return res;
}

int min_cardinality(int N){
	d = 0; n = N;
	srand(time(0));
	for(int i = 0; i < n; i++){
		p[i] = i;
	}
	random_shuffle(p, p + n);
	for(int i = N - 1; i >= 0; i--){
		add(p[i]);
		if(press_button() == 1) d++;
		else del(p[i]);
	} clear();
	int ans = 1;
	for(int l = 2, r = n / d; l <= r;){
		int mid = (l + r) >> 1;
		if(!ok(mid)) r = mid - 1;
		else l = mid + 1, ans = mid;
	}
	return ans;
}

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