Submission #1045262

#	Time	Username	Problem	Language	Result	Execution time	Memory
1045262		beaconmc	The Big Prize (IOI17_prize)	C++14	100 / 100	142 ms	2892 KiB

prize

#include "prize.h"

#include <bits/stdc++.h>

 
typedef int ll;
#define FOR(i,x,y) for(ll i=x; i<y; i++)
#define FORNEG(i,x,y) for(ll i=x; i>y; i--)
 
using namespace std;


map<ll, vector<ll>> cache;

vector<ll> query(int n){

	if (cache.count(n)) return cache[n];
	else return cache[n] = ask(n);
}


int find_best(int n) {
	cache.clear();
	vector<ll> stuff(n);
	vector<ll> newstuff(n);

	FOR(i,0,n) stuff[i] = i, newstuff[i] = i;
	ll maxi = -1;
	

	random_device rd;
    mt19937 g(rd());
 
    shuffle(newstuff.begin(), newstuff.end(), g);

	FOR(i,0,min(455, n)){
		vector<ll> sus = query(newstuff[i]);
		maxi = max(maxi, sus[0]+sus[1]);
	}
	

	vector<ll> found;

	ll ans = -1;


	while (ans == -1){


		ll lo = 0;
		ll hi = stuff.size()-1;
		bool skip = false;

		while (lo < hi){


			ll mid = (lo+hi)/2;
			ll cur = 1;
			while (cur < 10000){

				if (lo <= mid-cur && cache.count(stuff[mid-cur])){
					mid = mid-cur;
					break;
				}
				if (mid+cur < hi && cache.count(stuff[mid+cur])){
					mid = mid+cur;
					break;
				}
				cur++;
			}


			vector<ll> sus = query(stuff[mid]);


			if (sus[0] + sus[1] < maxi){
					
				if (sus[0]+sus[1]==0) return stuff[mid];
				found.push_back(stuff[mid]);
				stuff.erase(stuff.begin()+mid);
				skip = true;
				break;
			}else{
				sort(found.begin(), found.end());
				ll idk = upper_bound(found.begin(), found.end(), stuff[mid]) - found.begin();

				if (idk < sus[0]){
					hi = mid;
				}else{
					lo = mid+1;
				}
			}
		}

		if (skip) continue;

		vector<ll> sus = query(stuff[lo]);
		if (sus[0]+sus[1] == maxi) break;
		if (sus[0]+sus[1]==0) return stuff[lo];
		found.push_back(stuff[lo]);
		stuff.erase(stuff.begin()+lo);

	}

	return 0;

}

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