Submission #1030699

#	Time	Username	Problem	Language	Result	Execution time	Memory
1030699		ttamx	Colors (BOI20_colors)	C++17	0 / 100	1 ms	344 KiB

Colors

#include<bits/stdc++.h>

using namespace std;

using ll = long long;

const int LG=59;

inline int ask(int x){
    cout << "? " << x << endl;
    int res;
    cin >> res;
    return res;
}

int main(){
    cin.tie(nullptr)->sync_with_stdio(false);
    ll n;
    cin >> n;
    ll pos=1,dir=1,st=1,step=0;
    for(ll i=1LL<<LG;i>0;i>>=1){
        if(step+i>n-1)continue;
        step+=i;
        pos+=dir*step;
        if(pos>n){
            ll dif=pos-n;
            pos-=dif,st-=dif;
        }
        if(pos<1){
            ll dif=1-pos;
            pos+=dif,st+=dif;
        }
        dir=-dir;
    }
    ll ans=1;
    ask(st);
    dir=1,step=0;
    for(ll i=1LL<<LG;i>0;i>>=1){
        if(step+i>n-1)continue;
        st+=dir*i;
        if(!ask(st)){
            ans+=i;
            step+=i;
        }
        dir=-dir;
    }
    cout << "= " << ans << endl;
}

• Subtask 1: 0 / 9
• Subtask 2: 0 / 13
• Subtask 3: 0 / 21
• Subtask 4: 0 / 24
• Subtask 5: 0 / 33