Submission #1191024

#	Time	Username	Problem	Language	Result	Execution time	Memory
1191024		Zbyszek99	The Big Prize (IOI17_prize)	C++20	90.04 / 100	15 ms	780 KiB

prize

#include "prize.h"
#include <bits/stdc++.h>
#include <ext/pb_ds/assoc_container.hpp>
#include <ext/pb_ds/tree_policy.hpp>
#define ll long long
#define ld long double
#define ull unsigned long long
#define ff first
#define ss second
#define pii pair<int,int>
#define pll pair<long long, long long>
#define vi vector<int>
#define vl vector<long long>
#define pb push_back
#define rep(i, b) for(int i = 0; i < (b); ++i)
#define rep2(i,a,b) for(int i = a; i <= (b); ++i)
#define rep3(i,a,b,c) for(int i = a; i <= (b); i+=c)
#define count_bits(x) __builtin_popcountll((x))
#define all(x) (x).begin(),(x).end()
#define siz(x) (int)(x).size()
#define forall(it,x) for(auto& it:(x))
using namespace __gnu_pbds;
using namespace std;
typedef tree<int, null_type, less<int>, rb_tree_tag,tree_order_statistics_node_update> ordered_set;
mt19937 mt;void random_start(){mt.seed(chrono::time_point_cast<chrono::milliseconds>(chrono::high_resolution_clock::now()).time_since_epoch().count());}
ll los(ll a, ll b) {return a + (mt() % (b-a+1));}
const int INF = 1e9+50;
const ll INF_L = 1e18+40;
const ll MOD = 1e9+7;

map<int,pii> queryMap;
const int jump = 255;
int n;

pii query(int x)
{
	if(queryMap.find(x) != queryMap.end())
	{
		return queryMap[x];
	}
	vi a = ask(x);
	queryMap[x] = {a[0],a[1]};
	return {a[0],a[1]};
}

int get_worst_sum()
{
	int s = 0;
	rep(i,min(n,490))
	{
		pii a = query(i);
		s = max(s,a.ff+a.ss);
	}
	return s;
}

int find_best(int N) 
{
	n = N;
	random_start();
	int worst_sum = get_worst_sum();
	int cur_poz = 0;
	while(cur_poz < n)
	{
		pii x = query(cur_poz);
		if(x.ff + x.ss == 0) return cur_poz;
		if(x.ff + x.ss != worst_sum)
		{
			cur_poz++;
			continue;
		}
		int poz2 = min(n-1,cur_poz+jump);
		pii x2 = query(poz2);
		if(x2.ff + x2.ss == 0) return poz2;
		if(x.ff == x2.ff && x.ss == x2.ss)
		{
			cur_poz = poz2+1;
			continue;
		}
		int l = cur_poz;
		int r = poz2-1;
		int ans = -1;
		while(l <= r)
		{
			int mid = (l+r)/2;
			pii x2 = query(mid);
			if(x2.ff == x.ff && x2.ss == x.ss)
			{
				ans = mid;
				l = mid+1;
			}
			else
			{
				r = mid-1;
			}
		}
		cur_poz = ans+1;
	}
}

Compilation message (stderr)

prize.cpp: In function 'int find_best(int)':
prize.cpp:99:1: warning: control reaches end of non-void function [-Wreturn-type]
   99 | }
      | ^

• Subtask 1: 20 / 20
• Subtask 2: 70.04 / 80