Submission #524679

#	Time	Username	Problem	Language	Result	Execution time	Memory
524679		CSQ31	The Big Prize (IOI17_prize)	C++17	20 / 100	81 ms	328 KiB

prize

#include "prize.h"
#include <bits/stdc++.h>
using namespace std;
int num = 0;
#define sz(a) (int)(a.size());
int solve(int l,int r,int lf = 0,int rg = 0){
	//cout<<l<<" "<<r<<'\n';
	if(l > r)return -1;
	int mid = (l+r)/2;
	int i = 0;
	vector<int>res;
	for(i=mid;i<=r;i++){
		res = ask(i);
		if(!res[0] && !res[1])return i;
		else if(res[0] + res[1] == num)break;
	}
	if(i<=r){
		if(res[1]-rg){
			int c = solve(i+1,r,res[0],rg);
			if(c!=-1)return c;
		}
		if(res[0]-lf){
			int c = solve(l,mid-1,lf,res[1]);
			if(c!=-1)return c;
		}
		return -1;
	}else{
		for(i=mid-1;i>=l;i--){
			res = ask(i);
			if(!res[0] && !res[1])return i;
			else if(res[0] + res[1] == num)break;
		}
		if(i>=l && res[0]-lf)return solve(l,i-1,lf,res[1]);
		else return -1;
	}
}
mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());
int find_best(int n) {
	for(int i=0;i<10;i++){ //random until find dao biggest guy 
		int c = uniform_int_distribution<int>(0,n-1)(rng); 
		vector<int>res = ask(c);
		num = max(num,res[0]+res[1]);
	}
	//d&c to try all small guys since < #small guys < sqrt(n)
	int ans = solve(0,n-1);
	assert(ans!=-1);
	return ans;
}

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