Submission #1289008

#	Time	Username	Problem	Language	Result	Execution time	Memory
1289008		hiddenmeanings	Cave (IOI13_cave)	C++20	0 / 100	327 ms	520 KiB

cave

#include <bits/stdc++.h>
#include "cave.h"
using namespace std;

void exploreCave(int N) {
    int S[N], D[N];
    bool used[N] = {false};

    for (int door = 0; door < N; door++) {
        int comb[N];
        int l = 0, r = N - 1;
        int switchIndex = -1;

        // Binary search over unused switches
        while (l <= r) {
            int mid = (l + r) / 2;

            // Reset combination
            for (int i = 0; i < N; i++) {
                comb[i] = used[i] ? S[i] : 0;
            }

            // Set switches in range [l, mid] to 1
            for (int i = l; i <= mid; i++) {
                if (!used[i]) comb[i] = 1;
            }

            int result = tryCombination(comb);

            if (result == -1 || result > door) {
                // The switch is in [l, mid]
                r = mid;
            } else {
                // The switch is in [mid + 1, r]
                l = mid + 1;
            }

            if (l == r) {
                switchIndex = l;
                break;
            }
        }

        // Determine correct state of switch
        for (int i = 0; i < N; i++) {
            comb[i] = used[i] ? S[i] : 0;
        }

        comb[switchIndex] = 0;
        if (tryCombination(comb) == door) {
            S[switchIndex] = 1;
        } else {
            S[switchIndex] = 0;
        }

        D[switchIndex] = door;
        used[switchIndex] = true;
    }

    answer(S, D);
}

• Subtask 1: 0 / 12
• Subtask 2: 0 / 13
• Subtask 3: 0 / 21
• Subtask 4: 0 / 30
• Subtask 5: 0 / 24