Submission #562744

#	Time	Username	Problem	Language	Result	Execution time	Memory
562744		four_specks	Cave (IOI13_cave)	C++17	100 / 100	498 ms	460 KiB

cave

#include "cave.h"

#include <bits/stdc++.h>

using namespace std;

namespace
{
} // namespace

void exploreCave(int N)
{
    vector<int> s(N);
    vector<int> d(N);

    vector<int> guess(N, 0);

    vector<bool> done(N, 0);

    auto toggle = [&](int l, int r) -> void
    {
        for (int i = l; i < r; i++)
        {
            if (!done[i])
                guess[i] ^= 1;
        }
    };

    for (int i = 0; i < N; i++)
    {
        int lo = 1, hi = N;

        bool last = (tryCombination(guess.data()) + N + 1) % (N + 1) > i;
        while (lo < hi)
        {
            int mid = (lo + hi) / 2;
            toggle(0, mid);
            if (last != (tryCombination(guess.data()) + N + 1) % (N + 1) > i)
            {
                last = !last;
                hi = mid;
            }
            else
                lo = mid + 1;
        }

        s[lo - 1] = guess[lo - 1] ^ !last;
        d[lo - 1] = i;
        done[lo - 1] = 1;
        guess[lo - 1] = s[lo - 1];
    }

    answer(s.data(), d.data());
}

Compilation message (stderr)

cave.cpp: In function 'void exploreCave(int)':
cave.cpp:38:74: warning: suggest parentheses around comparison in operand of '!=' [-Wparentheses]
   38 |             if (last != (tryCombination(guess.data()) + N + 1) % (N + 1) > i)
      |                         ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~^~~

• Subtask 1: 12 / 12
• Subtask 2: 13 / 13
• Subtask 3: 21 / 21
• Subtask 4: 30 / 30
• Subtask 5: 24 / 24