Submission #1049602

#	Time	Username	Problem	Language	Result	Execution time	Memory
1049602		LittleOrange	The Big Prize (IOI17_prize)	C++17	20 / 100	1 ms	2040 KiB

prize

#include "prize.h"
#include<bits/stdc++.h>
using namespace std;
using ll = int;
int find_best(int n) {
	mt19937_64 mt(random_device{}());
	vector<array<ll,2>> mem(n,{-1,-1});
	auto qry = [&](ll i){
		if (mem[i][0]==-1){
			auto a = ask(i);
			mem[i] = {a[0],a[1]};
		}
		return mem[i];
	};
	/*
	ll cnt = 0;
	vector<ll> a(n);
	iota(a.begin(),a.end(),0);
	shuffle(a.begin(),a.end(),mt);*/
	ll ans = -1;
	function<void(ll,ll)> dfs;
	dfs = [&](ll l, ll r){
		if (ans != -1) return;
		if (l == r){
			ans = l;
			return;
		}
		ll m = l+r>>1;
		auto o = qry(m);
		if (o[0]+o[1]==0) {
			ans = m;
			return;
		}
		if (o[0]){
			dfs(l,m-1);
		}
		if(o[1]){
			dfs(m+1,r);
		}
	};
	dfs(0,n-1);
	return ans;
}

Compilation message (stderr)

prize.cpp: In lambda function:
prize.cpp:28:11: warning: suggest parentheses around '+' inside '>>' [-Wparentheses]
   28 |   ll m = l+r>>1;
      |          ~^~

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