1592E - Bored Bakry - CodeForces Solution

#include<bits/stdc++.h>
#define fo(i,x,y)for(int i=x;i<=y;++i)
using namespace std;
const int N=1<<20|1;
int a[N],n,b[N],c[N],ti,ans;
int main(){
    cin>>n;
    fo(i,1,n) cin>>a[i];
    fo(j,0,19){
        fo(i,1,n){
            ++ti;
            int sum=0;
            while(i<=n&&a[i]>>j&1){
                if(c[sum]<ti)b[sum]=i,c[sum]=ti;
                sum^=a[i]>>j;
                if(c[sum]==ti) ans=max(ans,i-b[sum]+1);
                i++;
                
            }
        }
    }
    cout<<ans;
    return 0;
}