#include <bits/stdc++.h>
#define pb push_back
#define fst first
#define snd second
#define fore(i,a,b) for(ll i=a,isudgh=b;i<isudgh;i++)
#define SZ(x) ((int)(x).size())
#define ALL(x) x.begin(),x.end()
#define mset(a,v) memset((a),(v),sizeof(a))
#define imp(v) {for(auto jhglkdfjg:v)cout<<jhglkdfjg<<" ";cout<<"\n";}
#define FIN ios::sync_with_stdio(0);cin.tie(0);cout.tie(0)
using namespace std;
typedef long long ll;
typedef pair<ll,ll> ii;
set<ll>st;
ll ask(ll c){
assert(!st.count(c));
st.insert(c);
cout<<"? "<<c+1<<endl;
ll ret; cin>>ret;
return ret;
}
void bf(ll n){
ask(0);
ll col=0,res=1;
for(ll i=n-1;i>0;i--){
ll c=col+(i%2==n%2?-i:i);
if(!ask(c)){
res=i+1;
break;
}
col=c;
}
cout<<"= "<<res<<endl;
}
random_device rd;
mt19937 rng(rd());
int main(){FIN;
ll n; cin>>n;
if(n<=64)bf(n);
ll l=1,r=n-1;
while(l<=r){
ll m=(l+r)/2;
ll p=-1;
fore(i,0,n)if(!st.count(i)&&rng()&1){p=i;ask(i);break;}
fore(i,0,n){
auto tray=[&](ll x){
x+=p;
if(x>=0&&x<n&&!st.count(x))return 1;
return 0;
};
vector<ll>magic={m+i,m-i}; shuffle(ALL(magic),rng);
if(tray(magic[0])){m=magic[0];break;}
if(tray(magic[1])){m=magic[1];break;}
}
if(ask(p+m))r=m-1;
else l=m+1;
}
cout<<l<<"\n";
return 0;
}
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
1 ms |
344 KB |
Execution killed with signal 13 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
1 ms |
344 KB |
Execution killed with signal 13 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
1 ms |
344 KB |
Execution killed with signal 13 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
1 ms |
344 KB |
Execution killed with signal 13 |
| 2 |
Halted |
0 ms |
0 KB |
- |
| # |
결과 |
실행 시간 |
메모리 |
Grader output |
| 1 |
Runtime error |
1 ms |
344 KB |
Execution killed with signal 13 |
| 2 |
Halted |
0 ms |
0 KB |
- |
