Submission #102948

#	Time	Username	Problem	Language	Result	Execution time	Memory
102948		briansu	The Big Prize (IOI17_prize)	C++14	100 / 100	49 ms	3584 KiB

prize

//{
#include<bits/stdc++.h>
using namespace std;
typedef long long ll;
typedef double lf;
typedef pair<ll,ll> ii;
#define REP(i,n) for(ll i=0;i<n;i++)
#define REP1(i,n) for(ll i=1;i<=n;i++)
#define FILL(i,n) memset(i,n,sizeof i)
#define X first
#define Y second
#define SZ(_a) (int)_a.size()
#define ALL(_a) _a.begin(),_a.end()
#define pb push_back
#ifdef brian
#define debug(...) do{\
    fprintf(stderr,"%s - %d (%s) = ",__PRETTY_FUNCTION__,__LINE__,#__VA_ARGS__);\
    _do(__VA_ARGS__);\
}while(0)
template<typename T>void _do(T &&_x){cerr<<_x<<endl;}
template<typename T,typename ...S> void _do(T &&_x,S &&..._t){cerr<<_x<<" ,";_do(_t...);}
template<typename _a,typename _b> ostream& operator << (ostream &_s,const pair<_a,_b> &_p){return _s<<"("<<_p.X<<","<<_p.Y<<")";}
template<typename It> ostream& _OUTC(ostream &_s,It _ita,It _itb)
{
    _s<<"{";
    for(It _it=_ita;_it!=_itb;_it++)
    {
        _s<<(_it==_ita?"":",")<<*_it;
    }
    _s<<"}";
    return _s;
}
template<typename _a> ostream &operator << (ostream &_s,vector<_a> &_c){return _OUTC(_s,ALL(_c));}
template<typename _a> ostream &operator << (ostream &_s,set<_a> &_c){return _OUTC(_s,ALL(_c));}
template<typename _a,typename _b> ostream &operator << (ostream &_s,map<_a,_b> &_c){return _OUTC(_s,ALL(_c));}
template<typename _t> void pary(_t _a,_t _b){_OUTC(cerr,_a,_b);cerr<<endl;}
#define IOS()
#else
#define debug(...)
#define pary(...)
#define endl '\n'
#define IOS() ios_base::sync_with_stdio(0);cin.tie(0);
#endif // brian
//}


const ll MAXn=2e5+5,MAXlg=__lg(MAXn)+2;
const ll MOD=1000000007;
const ll INF=ll(1e15);

#include "prize.h"

ii save[MAXn];

ii myask(ll x)
{
	if(save[x].X != -1)return save[x];
	else {
		auto v = ask(x);
		return save[x] = ii(v[0], v[1]);
	}
}

ll mxcnt, ans;

void loot(ll x)
{
	if(myask(x).X + myask(x).Y == 0)ans = x;
}

void go(int l, int r, int ct, int pre)
{
	if(r < l || ct <= 0)return;
	ll h = (l + r) / 2;
	ii p = myask(h);
	if(p.X + p.Y == mxcnt){
		go(l, h-1, p.X - pre, pre);
		go(h+1, r, ct - (p.X - pre), p.X);
	}else{
		loot(h);
		for(int i = h+1;i <= r;i ++)
		{
			ii pp = myask(i);
			if(pp.X + pp.Y == mxcnt){
				go(i+1, r, ct- (pp.X - pre), p.X);
				break;
			}
			else loot(i);
		}
		for(int i = h-1;i >= l;i --)
		{
			ii pp = myask(i);
			if(pp.X + pp.Y == mxcnt){
				go(l, i-1, pp.X - pre, pre);
				break;
			}
			else loot(i);
		}
	}
}

int find_best(int n) {
	REP(i,n)save[i] = ii(-1, -1);
	ll start = -1;
	ll s = max(0, n / 2 - 500);
	for(int i = s;i < s + 1000 && i < n;i ++){
		auto p = myask(i);
		mxcnt = max(mxcnt, p.X + p.Y);
		if(p.X + p.Y == mxcnt) start = i;
		if(n >= 20000 && ((mxcnt - 10) * (mxcnt - 10) + 1) * ((mxcnt - 10) * (mxcnt - 10) + 1) + 1 > n)break;
	}
	debug(start);
	ans = -2;
	go(0, start - 1, myask(start).X, 0);
	go(start + 1, n-1, myask(start).Y, myask(start).X);
	return ans;
}

• Subtask 1: 20 / 20
• Subtask 2: 80 / 80