Submission #850228

#	Time	Username	Problem	Language	Result	Execution time	Memory
850228		1075508020060209tc	Mađioničar (COI22_madionicar)	C++14	25 / 100	673 ms	17540 KiB

Main

#include<bits/stdc++.h>
using namespace std;
//#define int long long
map<pair<int,int>,int>mp;
map<pair<int,int>,int>vis;
int ask(int l,int r){
if(vis[{l,r}]){return mp[{l,r}];}
cout<<"? "<<l<<" "<<r<<endl;
int ret;
vis[{l,r}]=1;
cin>>ret;
mp[{l,r}]=ret;
return ret;
}
int n;
int ar[300005];
int par[300005];
int tar[500005];
void rebuild(){
tar[1]=ar[1];
int it=1;
for(int i=1;i<=n;i++){
    tar[it]=2;
    tar[it+1]=ar[i];
    it+=2;
}
tar[n+n+1]=2;
for(int i=1;i<=n+n+1;i++){
    ar[i]=tar[i];
}
 
}
 
signed main(){
cin>>n;
for(int i=1;i<=n-1;i++){
    int v=ask(i,i+1);
    if(v==1){
        ar[i+1]=ar[i];
    }else{
        ar[i+1]=ar[i]^1;
    }
}/*
for(int i=1;i<=n;i++){
    cout<<ar[i]<<" ";
}cout<<endl;*/
 
rebuild();
int l;int r;
l=-1;r=-1;
par[1]=1;//ar[n+n]=-1;
for(int i=2;i<=n+n+1;i++){
    if(r<i){
        int lit=i;int rit=i;
        par[i]=0;
        while(lit>=1&&rit<=n+n+1&&ar[lit]==ar[rit]){
            par[i]++;lit--;rit++;
        }
    }else{
        par[i]=min(par[l+r-i+1-1],r-i+1)-1;
        int lit=i-par[i];int rit=i+par[i];
        while(lit>=1&&rit<=n+n+1&&ar[lit]==ar[rit]){
            par[i]++;lit--;rit++;
        }
    }
    if(i+par[i]-1>r){
        l=i-par[i]+1;
        r=i+par[i]-1;
    }
}
int ans=0;
for(int i=1;i<=n+n-1;i++){
    ans=max(ans,par[i]);
   // cout<<ar[i]<<" ";
}/*cout<<endl;
for(int i=1;i<=n+n-1;i++){
    cout<<par[i]<<" ";
}cout<<endl;*/
cout<<"! "<<ans-1<<endl;
 
}

• Subtask 1: 0 / 13
• Subtask 2: 0 / 25
• Subtask 3: 25 / 25
• Subtask 4: 0 / 37