Submission #876342

#	Time	Username	Problem	Language	Result	Execution time	Memory
876342		abczz	The Big Prize (IOI17_prize)	C++14	20 / 100	39 ms	908 KiB

prize

#include "prize.h"
#include <iostream>
#include <vector>
#include <random>
#define ll long long
 
using namespace std;

ll f;
vector <int> R;
void solve(ll l, ll r, ll ql, ll qr) {
	if (l > r || ql + qr == R[0] + R[1]) return;
	ll mid = (l+r)/2;
	for (int i=mid; i<=r; ++i) {
		auto u = ask(i);
		if (!u[0] && !u[1]) {
			f = i;
			return;
		}
		else if (u[0]+u[1] == R[0]+R[1]) {
			solve(l, mid-1, ql, u[1]+(i-mid));
			if (f != -1) return;
			solve(i+1, r, u[0], qr);
			return;
		}
	}
	solve(l, mid-1, ql, qr+(r-mid+1));
}

int find_best(int n) {
  f = -1;
  random_device rd;
  mt19937 mt(rd());
  R = {-1, -1};
  for (int i=0; i<10; ++i) {
    ll id = mt() % n;
    auto u = ask(i);
    if (u[0]+u[1] > R[0]+R[1]) swap(u, R);
  }
	solve(0, n-1, 0, 0);
	return f;
}

Compilation message (stderr)

prize.cpp: In function 'int find_best(int)':
prize.cpp:36:8: warning: unused variable 'id' [-Wunused-variable]
   36 |     ll id = mt() % n;
      |        ^~

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