Submission #857982

#	Time	Username	Problem	Language	Result	Execution time	Memory
857982		firewater	Rarest Insects (IOI22_insects)	C++17	100 / 100	32 ms	948 KiB

insects

#include "insects.h"
#include<bits/stdc++.h>
#define MX 2023
using namespace std;
int n,m,l,r,num,sav,v[MX],p[MX],pp[MX];
vector<int>d;
int check(int x)
{
	for(int i=0;i<n;++i){
		if(p[v[i]]||pp[v[i]])continue;
		move_inside(v[i]);
		if(press_button()>x)move_outside(v[i]);
		else{
			p[v[i]]=1;
			d.push_back(v[i]);
			num++;
		}
		if(num==x*m)return num;
	}
	return num;
}
int min_cardinality(int N) {
	n=N;
	for(int i=0;i<n;++i)
		v[i]=i;
	random_shuffle(v,v+n);
	for(int i=0;i<n;++i){
		move_inside(v[i]);
		if(press_button()>1)move_outside(v[i]);
		else p[v[i]]=1,num++;
	}
	m=num;
	l=1;
	r=n/m;
	sav=-1;
	while(l<r){
		int mid=l+r+(r==l+1)>>1;
		mid=min(mid,r);
		d.clear();
		if(sav!=-1){
			d.push_back(sav);
			sav=-1;
		}
		if(check(mid)==mid*m)l=mid;
		else{
			r=mid-1;
			for(int i=0;i<n;++i)
				if(!p[v[i]])pp[v[i]]=1;
			for(int i=1;i<d.size();++i){
				p[d[i]]=0;
				move_outside(d[i]);
				num--;
			}
			sav=d[0];
		}
	}
	return l;
}

Compilation message (stderr)

insects.cpp: In function 'int min_cardinality(int)':
insects.cpp:37:14: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   37 |   int mid=l+r+(r==l+1)>>1;
      |           ~~~^~~~~~~~~
insects.cpp:49:17: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   49 |    for(int i=1;i<d.size();++i){
      |                ~^~~~~~~~~

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