Submission #1078325

#	Time	Username	Problem	Language	Result	Execution time	Memory
1078325		Faisal_Saqib	Rarest Insects (IOI22_insects)	C++17	100 / 100	504 ms	16216 KiB

insects

#include <bits/stdc++.h>
using namespace std;
void move_inside(int i);
void move_outside(int i);
int press_button();
mt19937 RNG(chrono::steady_clock::now().time_since_epoch().count());  
#define all(x) begin(x),end(x)
#define SHUFFLE(v) shuffle(all(v), RNG); 
set<int> machine,rem,real_;
void add(int x)
{
	if(machine.find(x)==machine.end())
	{
		machine.insert(x);
	}
}
void remp(int x)
{
	if(machine.find(x)!=machine.end())
	{
		machine.erase(x);
	}
}
map<vector<int>,int> store;
int ask()
{
	vector<int> cur(begin(machine),end(machine));
	if(store.find(cur)!=store.end())
		return store[cur];
	for(auto&i:real_)
		if(machine.find(i)==machine.end())
			move_outside(i);
	for(auto&i:machine)
		if(real_.find(i)==real_.end())
			move_inside(i);
	real_=machine;
	return store[cur]=press_button();
}
int min_cardinality(int n)
{

	for(int i=0;i<n;i++){rem.insert(i);}
	{
		vector<int> order(begin(rem),end(rem));
		add(order[0]);
		for(int i=1;i<n;i++)
		{
			add(order[i]);
			if(ask()>1)
			{
				remp(order[i]);
			}
		}
	}
	int sz=machine.size();
	int s=1;
	int e=(n/sz)+1;
	while(s+1<e)
	{
		int mid=(s+e)/2;
		vector<int> cur;
		vector<int> order(begin(rem),end(rem));
		SHUFFLE(order);
		for(auto&i:order)
		{
			if(machine.size()==(sz*mid))
				break;
			add(i);
			if(machine.size()>mid and ask()>mid)
			{
				remp(i);
			}
			else
			{
				cur.push_back(i);
				if(machine.size()==(sz*mid))
					break;
			}
		}
		if(machine.size()==((sz*mid)))
		{
			s=mid;
			for(auto&i:cur)
				rem.erase(i);
		}
		else{
			int szp=machine.size();
			e=min(mid,1+(szp/sz));
			rem.clear();
			for(auto&i:cur)
			{
				rem.insert(i);
				remp(i);
			}
		}
	}
	return s;
}

Compilation message (stderr)

insects.cpp: In function 'int min_cardinality(int)':
insects.cpp:66:21: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   66 |    if(machine.size()==(sz*mid))
      |       ~~~~~~~~~~~~~~^~~~~~~~~~
insects.cpp:69:21: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   69 |    if(machine.size()>mid and ask()>mid)
      |       ~~~~~~~~~~~~~~^~~~
insects.cpp:76:22: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   76 |     if(machine.size()==(sz*mid))
      |        ~~~~~~~~~~~~~~^~~~~~~~~~
insects.cpp:80:20: warning: comparison of integer expressions of different signedness: 'std::set<int>::size_type' {aka 'long unsigned int'} and 'int' [-Wsign-compare]
   80 |   if(machine.size()==((sz*mid)))
      |      ~~~~~~~~~~~~~~^~~~~~~~~~~~

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