#include<bits/stdc++.h> typedef long long ll; #define pb push_back #define fr first #define sc second #define endl '\n' using namespace std; #define mid ((left+right)>>1) #include "light.h" ll n=1; vector<ll>v; void prepare(){ v.pb(1); } void f(ll p){ vector<pair<ll,ll>>sta; for(int i=0;i<v.size();i++){ sta.pb({v[i],min(v[i]+p,n)}); } v.clear(); ll las=n; v.pb(n); while(sta.size()){ pair<ll,ll>x=sta.back(); sta.pop_back(); if(x.sc>=las)x.sc=las-1; if(x.fr>x.sc)continue; ll m=n-las+1; while(x.fr<=las-m-1){ las=las-m-1; m=n-las+1; v.pb(las); x.sc=las-1; if(x.fr>x.sc)break; } if(x.fr>x.sc)continue; if(!sta.size()||sta.back().sc<las-m-1){ las=x.fr; v.pb(las); } } reverse(v.begin(),v.end()); } pair<ll,vector<ll>> join(ll p){ n+=p; f(p); return {p,v}; } pair<ll,vector<ll>> leave(ll p){ n-=p; while(v.back()>n){ v.pop_back(); } f(p); return {p,v};; }