Submission #1243696

#	Time	Username	Problem	Language	Result	Execution time	Memory
1243696		lacito	Cave (IOI13_cave)	C++17	100 / 100	291 ms	532 KiB

cave

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

void exploreCave(int n) {
    int s[n];
    vector<int> switch_of_door(n, -1), correct(n, -1);
    for (int door = 0; door < n; door++) {
        for (int i = 0; i < n; i++) s[i] = 0;
        for (int j = 0; j < door; j++) s[switch_of_door[j]] = correct[j];
        int closed_idx = tryCombination(s);
        if (closed_idx == door) {
            correct[door] = 1;
        } else {
            correct[door] = 0;
        }

        int l = 0, r = n; // l <= answer < r
        while (r - l > 1) {
            int mid = (l + r) / 2;
            for (int i = 0; i < n; i++) s[i] = correct[door];
            for (int i = l; i < mid; i++) s[i] = !correct[door];
            for (int j = 0; j < door; j++) s[switch_of_door[j]] = correct[j];
            int closed_idx = tryCombination(s);
            if (closed_idx == door) {
                r = mid;
            } else {
                l = mid;
            }
        }
        switch_of_door[door] = l;
    }
    
    for (int i = 0; i < n; i++) s[i] = 0;
    int d[n];
    for (int i = 0; i < n; i++) {
        d[switch_of_door[i]] = i;
        s[switch_of_door[i]] = correct[i];
    }
    answer(s, d);
}

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