Submission #1025283

#	Time	Username	Problem	Language	Result	Execution time	Memory
1025283		Issa	Rarest Insects (IOI22_insects)	C++17	0 / 100	1 ms	344 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 mx[maxn];
int mn[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;
	for(int i = 0; i < n; i++){
		if(used[i]) continue;
		add(i);
		if(press_button() > k){
			del(i);
		} else{
			if(f[i]){
				res = 1;
				break;
			} else if(sz >= 1ll * d * k){
				res = 0;
				break;
			}
		}
	}
	if(res){
		for(int i = 0; i < n; i++){
			if(used[i] == 1){
				del(i);
			} else if(used[i] == 0){
				used[i] = 2;
			}
		}
	} else{
		for(int i = 0; i < n; i++){
			if(used[i]) used[i] = 2;
		}
	}
	return res;
}

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

Compilation message (stderr)

insects.cpp: In function 'int min_cardinality(int)':
insects.cpp:77:7: warning: the address of 'bool ok(int)' will never be NULL [-Waddress]
   77 |   if(!ok) l = mid + 1;
      |       ^~
insects.cpp: In function 'bool ok(int)':
insects.cpp:51:2: warning: 'res' may be used uninitialized in this function [-Wmaybe-uninitialized]
   51 |  if(res){
      |  ^~

• Subtask 1: 0 / 10
• Subtask 2: 0 / 15
• Subtask 3: 0 / 75