Submission #471353

#	Time	Username	Problem	Language	Result	Execution time	Memory
471353		dxz05	The Big Prize (IOI17_prize)	C++14	90 / 100	115 ms	12556 KiB

prize

#include "prize.h"
#include <bits/stdc++.h>

using namespace std;

const int MAXN = 5e5 + 3e2;
typedef long long ll;

//mt19937 rng(chrono::high_resolution_clock::now().time_since_epoch().count());

vector<int> asked_values[MAXN];

int cnt = 0;
vector<int> ASK(int i){
    vector<int> res;
    if (asked_values[i].empty()){
        cnt++;
        assert(cnt <= 10000);
        res = ask(i);
        asked_values[i] = res;
        //cout << i << ' ' << res.front() << ' ' << res.back() << endl;
    } else res = asked_values[i];
    return res;
}

int find_best(int n) {
    vector<int> res;

    int mx = 0;
    int pos = 0;
    while (pos < 500){
        ASK(pos);
        res = ASK(pos);
        if (res[0] + res[1] == 0) return pos;
        mx = max(mx, res[0] + res[1]);
        pos++;
    }

    while (pos < n){
        res = ASK(pos);
        if (res[0] + res[1] == 0) return pos;
        if (res[0] + res[1] < mx){
            pos++;
            continue;
        }

        int nxt = pos + 1;
        int l = pos + 1, r = n - 1;
        while (l <= r){
            int m = (l + r) >> 1;
            res = ASK(m);
            if (res[0] + res[1] == 0) return m;
            if (res[0] + res[1] < mx){
                r = m - 1;
                nxt = m;
            } else {
                auto tmp = ASK(pos);
                if (res[0] == tmp[0]) l = m + 1; else
                    r = m - 1;
                nxt = m + 1;
            }
        }

        pos = nxt;
    }

    return n / 2;
}

• Subtask 1: 20 / 20
• Subtask 2: 70 / 80