Submission #831240

#	Time	Username	Problem	Language	Result	Execution time	Memory
831240		Username4132	Counting Mushrooms (IOI20_mushrooms)	C++17	0 / 100	7 ms	312 KiB

mushrooms

#include "mushrooms.h"
#include<iostream>
#include<vector>
using namespace std;
#define forn(i, n) for(int i=0; i<(int)n; ++i)
#define forsn(i, s, n) for(int i=s; i<(int)n; ++i)
#define PB push_back

const int SZ = 135;

int count_mushrooms(int n) {
	if(n==2) return use_machine({0, 1}) + 1;



	int a, b, f, s, type, pen = min(2*SZ + 3, n);
	a = use_machine({0, 1});
	b = use_machine({0, 2});
	if(a==0) f=0, s=1, type=0;
	else if(b==0) f=0, s=2, type=0;
	else f=1, s=2, type=1;

	vector<bool> res(pen);
	res[0]=0, res[1]=a, res[2]=b;

	for(int i=3; i<pen; i+=2){
		if(i+1<pen){
			int ret = use_machine({f, i, s, i+1});
			res[i]=(ret>>1)^type, res[i+1]=(ret&1)^type;
		}
		else{
			int ret = use_machine({f, i, s});
			res[i]=(ret>>1)^type;
		}
	}
	int tot=0, ans=0;
	vector<int> toUse;
	forn(i, pen) tot+=res[i];
	bool cond = 2*tot > pen;
	forn(i, pen) if(res[i] == cond) toUse.PB(i);
	forn(i, pen) ans+=!res[i];
	int sz = (int)toUse.size(), l=pen;
	while(l<n){
		vector<int> ask;
		int r = min(l+sz, n);
		forn(i, r-l){
			ask.PB(toUse[i]);
			ask.PB(l+i);
		}
		int ret = use_machine(ask);
		int ad = ((ret+1)>>1);
		ans+=(cond? ad : r-l-ad);
		l=r;
	}
	return ans;
}

• Subtask 1: 0 / 100