Submission #667149

#	Time	Username	Problem	Language	Result	Execution time	Memory
667149		Darren0724	Colors (BOI20_colors)	C++17	100 / 100	4 ms	336 KiB

Colors

#include<bits/stdc++.h>
using namespace std;
#define int long long
#define all(x) x.begin(),x.end()
 
signed main(){
    ios_base::sync_with_stdio(false);
    cin.tie(0);
    int n;cin>>n;
    int l=0,r=n;
    vector<int> v;
    while(r-l>1){
        int m=(l+r)>>1;
        v.push_back(m);
        l=m;
    }
    bool flag=0;
    int s=n;
    int n1=v.size();
    for(int i=n1-1;i>=0;i--){
        if(flag==0){
            s-=v[i];
        }
        else{
            s+=v[i];
        }
        flag^=1;
    }
    cout<<"? "<<s<<endl;
 
    int b=0;
    cin>>b;
    l=0,r=n;
    while(r-l>1){
        int m=(l+r)>>1;
        if(flag==1){
            s+=m;
        }
        else{
            s-=m;
        }
        flag^=1;
        cout<<"? "<<s<<endl;
        int k;cin>>k;
        if(k==1){
            r=m;
        }
        else{
            l=m;
        }
    }
    cout<<"= "<<r<<endl;
 
 
    return 0;
}

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