Submission #547461

#	Time	Username	Problem	Language	Result	Execution time	Memory
547461		Monarchuwu	The Big Prize (IOI17_prize)	C++17	0 / 100	74 ms	288 KiB

prize

#include "prize.h"
using namespace std;

int _n, ans;
bool lollipop(int k) { return k * 2 >= _n; }
bool dnc(int l, int r, int cntl, int cntr) {
    if (l > r) return false;

    int m = (l + r) >> 1;
    int p = m;
    vector<int> a;
    while (p <= r) {
        a = ask(p);
        if (a[0] + a[1] == 0) { ans = p; return true; }
        if (lollipop(a[0] + a[1])) break;
        ++p;
    }

    if (p <= r) {
        // [l, m-1] and [p+1, r]
        if (a[0] - (p - m) > cntl && dnc(l, m - 1, cntl, a[1] + (p - m))) return true;
        if (a[1] > cntr && dnc(p + 1, r, a[0], cntr)) return true;
    }
    else {
        if (dnc(l, m - 1, cntl, cntr + (p - m))) return true;
    }
    return false;
}
int find_best(int N) {
    _n = N;
    dnc(0, _n - 1, 0, 0);
    return ans;
}

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