Submission #38434

#	Time	Username	Problem	Language	Result	Execution time	Memory
38434		MatheusLealV	The Big Prize (IOI17_prize)	C++14	90 / 100	76 ms	8552 KiB

prize

#include <bits/stdc++.h>
#include "prize.h"
#define N 200050
using namespace std;

int n, v[N], maior, ans, raiz;

vector<int> dp[N];

vector<int> aski(int x)
{
	if(!dp[x].empty()) return dp[x];

	return dp[x] = ask(x);
}

#define f first
#define s second
typedef pair<int, int> pii;

vector<int> bucket[500];

int solve(int p, int en)
{
    while(p <= en)
    {
        vector<int> aux = aski(p);

        if(aux[0] + aux[1] == 0) return p;

        int ini = p + 1, fim = en, mid;

        if(aux[0] + aux[1] == maior)
        {
            while(fim >= ini)
            {
                mid = (ini + fim)/2;

                vector<int> atual = aski(mid);

                if(atual[0] + atual[1] == 0) return mid;

                if(ini == fim) break;

                if(atual[0] + atual[1] < maior) fim = mid;
                else
                {
                    if(aux[1] - atual[1] > 0) fim = mid - 1;
                    else ini = mid + 1;
                }
            }

            p = ini + 1;

        } else p++;
    }

    return -1;
}

int find_best(int n)
{
	raiz = 500;

	for(int i = 0; i < n; i ++ ) bucket[i/raiz].push_back(i);

	for(int i = 0; i < raiz; i++)
	{
		vector<int> aux = aski(i);

		if(aux[0] + aux[1] == 0) return i;

		maior = max(maior, aux[0] + aux[1]);
	}

	for(int i = 0; i < 500; i++)
	{
		if(bucket[i].empty()) continue;

		int a = bucket[i][0], b = bucket[i].back();

		int ans = solve(a, b);

		if(ans > -1) return ans;
	}

	return -1;
}

• Subtask 1: 20 / 20
• Subtask 2: 70 / 80