Submission #914235

#	Time	Username	Problem	Language	Result	Execution time	Memory
914235		edogawa_something	Colors (BOI20_colors)	C++17	0 / 100	1 ms	344 KiB

Colors

#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef vector<ll> vii;
typedef pair<ll,ll> pii;
#define F first
#define S second
#define pb push_back
#define all(v) v.begin(),v.end()
#define pow poww
const ll M=1e5+10;
const ll inf=2e18;
const ll mod=1e9+7;
ll pow(ll x,ll y){
  ll res=1;
  x%=mod; 
  while(y>0){
    if((y&1))
    res*=x,res%=mod;
    x*=x,x%=mod;
    y=(y>>1);
  }
  return res;
}
ll n,ans,cn;
bool ask(ll x){
  cout<<"? "<<x<<endl;
  bool c;
  cin>>c;
  return c;
}
void ret(ll x){
  cout<<"= "<<x<<endl;
}
int main(){
  ios_base::sync_with_stdio(0),cin.tie(0);
  ll TC=1;
  //cin>>TC;
  while(TC--){
    cin>>n;
    ll x;
    ll l=1,r=n-1,mid;
    for(int i=0;i<64;i++){
      if((1<<i)>n-1){
      cn=i;
      break;
      }
    }
    ask(n-(1<<(cn-1)));
    x=n-(1<<(cn-1));
    bool c=1;
    ll cur=0;
    while(l<=r){
      cn--;
      if(cn==-1)
      break;
      c^=1;
      if(c){
        if(x-cur-(1<<cn)<1)
        continue;
        if(ask(x-cur-(1<<cn)))
        cur+=(1<<cn);
        x-=cur;
      }
      else{
        if(x+cur+(1<<cn)>n)
        continue;
        if(ask(x+cur+(1<<cn)))
        cur+=(1<<cn);
        x+=cur;
      }
    }
    ret(cur);
  }
  return 0;
}
/*

*/  

Compilation message (stderr)

Colors.cpp: In function 'int main()':
Colors.cpp:42:18: warning: unused variable 'mid' [-Wunused-variable]
   42 |     ll l=1,r=n-1,mid;
      |                  ^~~

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