Submission #1035388

#	Time	Username	Problem	Language	Result	Execution time	Memory
1035388		Gray	Counting Mushrooms (IOI20_mushrooms)	C++17	75.59 / 100	6 ms	600 KiB

mushrooms

#include "mushrooms.h"

#define ff first
#define ss second
#define ll int
#define ln "\n"

using namespace std;

int qry=200;

int count_mushrooms(int n) {
	std::vector<int> query;
	vector<int> as, bs;
	as.push_back(0);

	for (ll i=1; i<=min(2, n-1); i++){
		query = {0, int(i)};
		ll ret = use_machine(query);
		if (ret==0) as.push_back(i);
		else bs.push_back(i);
	}
	for (ll i=3; i<min(qry+1, n); i+=2){
		if (i+1<min(qry+1, n)){
			if (as.size()>bs.size()){
				query = {i, as[0], i+1, as[1]};
				ll ret = use_machine(query);
				if (ret==0){
					as.push_back(i);
					as.push_back(i+1);
				}else if (ret==1){
					as.push_back(i+1);
					bs.push_back(i);
				}else if (ret==2){
					as.push_back(i);
					bs.push_back(i+1);
				}else{
					bs.push_back(i);
					bs.push_back(i+1);
				}
			}else{
				query = {i, bs[0], i+1, bs[1]};
				ll ret = use_machine(query);
				if (ret==0){
					bs.push_back(i);
					bs.push_back(i+1);
				}else if (ret==1){
					bs.push_back(i+1);
					as.push_back(i);
				}else if (ret==2){
					bs.push_back(i);
					as.push_back(i+1);
				}else{
					as.push_back(i);
					as.push_back(i+1);
				}
			}
		}else{
			query = {0, (int)i};
			ll ret = use_machine(query);
			if (ret==0) as.push_back(i);
			else bs.push_back(i);
		}
	}
	


	ll ans=(ll)as.size();
	if (as.size()>bs.size()){
		for (ll i=min(qry+1, n); i<n; i+=as.size()-1){
			query.clear();
			for (ll j=0; j<(ll)as.size()-1 and i+j<n; j++){
				query.push_back(as[j]);
				query.push_back(i+j);
			}
			query.push_back(as.back());
			ll ret = use_machine(query)/2ll;
			ans+=(query.size()-1)/2-ret;
		}
	}else{
		for (ll i=min(qry+1, n); i<n; i+=bs.size()-1){
			query.clear();
			for (ll j=0; j<(ll)bs.size()-1 and i+j<n; j++){
				query.push_back(bs[j]);
				query.push_back(i+j);
			}
			query.push_back(bs.back());
			ll ret = use_machine(query)/2ll;
			ans+=ret;
		}
	}
	return ans;
}

• Subtask 1: 75.5853 / 100