Submission #405374

#	Time	Username	Problem	Language	Result	Execution time	Memory
405374		dxz05	The Big Prize (IOI17_prize)	C++14	20 / 100	26 ms	12128 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());

int foo, hoo;

vector<int> asked_values[MAXN];

int calls_count = 0;

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

    foo = res.front();
    hoo = res.back();
    asked_values[i] = res;

}

int find_best(int n) {
    int mx = 0;
    for (int i = 0; i < 1000; i++){
        int x = rng() % n;
        ASK(x);
        if (foo + hoo == 0) return x;
        mx = max(mx, foo + hoo);
    }

    int cur = 0;
	for (int i = 0; i < n; i++){
        int l = i, r = n - 1;
        int idx = n;
        while (l <= r){
            int m = (l + r) >> 1;
            ASK(m);
            if (foo + hoo == 0) return m;

            //cout << i << ' ' << l << ' ' << r << ' ' << m << ' ' << foo << ' ' << hoo << endl;

            if (foo + hoo < mx){
                idx = m;
                if (foo == cur) break;
            }

            if (foo > cur){
                r = m - 1;
            } else l = m + 1;
        }
        i = idx;
        cur++;
	}

	//assert(false);

	return 0;
}

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