제출 #524844

#	제출 시각	아이디	문제	언어	결과	실행 시간	메모리
524844		CSQ31	커다란 상품 (IOI17_prize)	C++17	20 / 100	82 ms	6016 KiB

prize

#include "prize.h"
#include <bits/stdc++.h>
using namespace std;
int num = 0;
#define sz(a) (int)(a.size());
vector<int>res[200000];
int cnt = 0;
int solve(int l,int r,int lf = 0,int rg = 0){
	if(l > r)return -1;
	int mid = (l+r)/2;
	for(int i=0;i<=r-l;i++){
		int ml = mid-i/2;
		int mr = mid+(i+1)/2;
		int m = i%2==0?ml : mr;
		int tmpl = i%2==0?0:mr-ml;
		int tmpr = i%2==1?0:mr-ml;
		res[m] = ask(m);
		if(!res[m][0] && !res[m][1])return m;
		if(res[m][0] + res[m][1] == num){
			int c = -1;
		     if(res[m][0]-tmpl>lf)c = max(c,solve(l,ml-1,lf,res[m][1]+tmpl));
	         if(res[m][1]-tmpr>rg)c = max(c,solve(mr+1,r,res[m][0]+tmpr,rg));
	         return c;
	         
		}
	}
	return -1;
		
}
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
int find_best(int n) {
	vector<int>a(n);
	for(int i=0;i<n;i++)a[i] = i;
	shuffle(a.begin(),a.end(),rng);
	for(int i=0;i<min(100,n);i++){
		vector<int>res = ask(a[i]);
		num = max(num,res[0] + res[1]);
	}
	
	//d&c to try all small guys since < #small guys < sqrt(n)
	return solve(0,n-1);
}

• Subtask 1: 20 / 20
• Subtask 2: 0 / 80