Submission #502484

#	Time	Username	Problem	Language	Result	Execution time	Memory
502484		IOI_champion_in_1980	Colors (BOI20_colors)	C++14	100 / 100	3 ms	344 KiB

Colors

#include <bits/stdc++.h>
typedef long long ll;
using namespace std;
ll a, b, c, d, e, n, m, l, r, mid, ind, pos;
bool barla(long long k)
{
	bool ret;
	cout<<"? "<<k<<endl;
	cin>>ret;
	return ret;
}
int main()
{
    cin>>n;
	l=1; r=n; 
	pos=-1; ind=pos;
	long long bir=1;
	while (l<r)
	{
		mid=(l+r-1)/2;
		ind=ind+(bir*mid);
		pos=min(pos, ind);
		l=mid+1;
		bir=bir*(-1);
	}
	pos=abs(pos);
	barla(pos);
	
	l=1; r=n; bir=1;
	bool hakyky=false;
	while (l<r)
	{
		mid=(l+r-1)/2;
		pos=pos+(bir*mid);
		hakyky=barla(pos);
		if (hakyky) r=mid;
			else l=mid+1;
		bir=bir*(-1);
	}
	cout<<"= "<<l<<endl;
}

• Subtask 1: 9 / 9
• Subtask 2: 13 / 13
• Subtask 3: 21 / 21
• Subtask 4: 24 / 24
• Subtask 5: 33 / 33