Submission #778636

#	Time	Username	Problem	Language	Result	Execution time	Memory
778636		benjaminkleyn	The Big Prize (IOI17_prize)	C++17	20 / 100	79 ms	1788 KiB

prize

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

bool asked[200000] = {false};
int L[200000], R[200000];

bool Ask(int i)
{
    if (asked[i]) return L[i] + R[i] == 0;
    asked[i] = true;
    vector<int> res = ask(i);
    L[i] = res[0], R[i] = res[1];
    return L[i] + R[i] == 0;
}

int Find(int l, int r)
{
    int m = (l + r) / 2;
    if (Ask(m)) return m;
    if (R[l] == R[r] && L[r] == L[l]) return -1;

    int x = Find(l, m);
    if (x >= 0) return x;

    if (Ask(m+1)) return m+1;

    int y = Find(m + 1, r);
    if (y >= 0) return y;

    return -1;
}

int find_best(int n) 
{
    if (Ask(0)) return 0;
    if (Ask(n-1)) return n-1;
    return Find(0, n - 1);
}

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