Submission #357683

#	Time	Username	Problem	Language	Result	Execution time	Memory
357683		leinad2	Colors (BOI20_colors)	C++17	0 / 100	1 ms	364 KiB

Colors

#include<bits/stdc++.h>
using namespace std;
int n, b, i, j, k, c, chk[111], x, y, prv, cnt;
int ask(int x)
{
    cout<<"? "<<x<<endl;
    int ret;
    cin>>ret;
    return ret;
}
int main()
{
    ios_base::sync_with_stdio(false);cin.tie(NULL);cout.tie(NULL);
    cin>>n;
    b=(int)sqrt(n);
    vector<int>v;
    for(i=1;i<n;i+=b)v.push_back(i);
    x=(n-v.back()+1)/2;
    for(i=0;i<v.size();i++)v[i]+=x;
    for(k=1;;k++)
    {
        i=k/2;
        if(k%2)j=i;
        else j=v.size()-i;
        if(chk[v[j]])break;
        int ret=ask(v[j]);
        prv=v[j];
        if(k==1)continue;
        if(ret==0)
        {
            if(k%2==0)c=v.size()-2*i+1;
            else c=v.size()-2*i;
            break;
        }
    }
    v.clear();
    x=c*b+1;
    y=min((c+1)*b, n-1);
    if(2*prv>n)cnt=-1;
    else cnt=1;
    for(i=x;i<=y;i++)
    {
        int ret=ask(prv+cnt*i);
        prv+=cnt*i;
        cnt=-cnt;
        if(ret)break;
    }
    cout<<"= "<<i;
}

Compilation message (stderr)

Colors.cpp: In function 'int main()':
Colors.cpp:19:14: warning: comparison of integer expressions of different signedness: 'int' and 'std::vector<int>::size_type' {aka 'long unsigned int'} [-Wsign-compare]
   19 |     for(i=0;i<v.size();i++)v[i]+=x;
      |             ~^~~~~~~~~

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