Submission #648084

#	Time	Username	Problem	Language	Result	Execution time	Memory
648084		Clan328	Cave (IOI13_cave)	C++17	100 / 100	412 ms	460 KiB

cave

#include "cave.h"
#include "bits/stdc++.h"

using namespace std;

typedef vector<int> vi;

#define DOWN 1
#define UP 0
#define NA 2

int n;
vi dir;

int check(int tmp, int lo, int mid, int hi) {
    int arr[n];
    for (int i = 0; i <= mid; i++) {
        if (dir[i] == NA) arr[i] = 1-tmp;
        else arr[i] = dir[i];
    }
     for (int i = mid+1; i < n; i++) {
        if (dir[i] == NA) arr[i] = tmp;
        else arr[i] = dir[i];
    }

    // for (int i = 0; i < n; i++) {
    //     cout << (arr[i] == UP? "UP" : "DOWN") << " ";
    // }
    // cout << endl;

    return tryCombination(arr);
}

void exploreCave(int N) {
    int S[N];
    int D[N];
    dir = vi(N, NA); // Dir to open door

    n = N;

    for (int i = 0; i < N; i++) {
        D[i] = -1;
    }

    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            S[j] = DOWN;
            if (dir[j] != NA) S[j] = dir[j];
        }
        // for (int j = 0; j < N; j++) {
        //     if (D[j] != -1) S[D[j]] = dir[j];
        // }
        // cout << S[2] << endl;
        // for (int j = 0; j < N; j++) {
        //     cout << (S[j] == UP? "UP" : "DOWN") << " ";
        // }
        // cout << endl;

        int tmp = tryCombination(S);
        int tmpDir;
        if (tmp == i) {
            tmpDir = UP;
        } else
            tmpDir = DOWN;
        // cout << tmpDir << endl;
        int lo = 0, hi = N-1, mid;
        while (lo < hi) {
            mid = (lo+hi)/2;

            bool isDownI = check(tmpDir, lo, mid, hi) == i;
            // cout << lo << " " << mid << " " << isDownI << endl;
            if (isDownI) {
                hi = mid;
            } else
                lo = mid + 1;
        }
        D[lo] = i;
        if (tmp == i) {
            dir[lo] = UP;
        } else
            dir[lo] = DOWN;
        // cout << (dir[i] == UP? "UP" : "DOWN") << endl;
        // cout << "x: " << lo << endl;
    }

    for (int i = 0; i < N; i++) S[i] = dir[i];

    // int res[N];
    // for (int i = 0; i < N; i++) res[i] = dir[D[i]];

    // for (int i = 0; i < N; i++) {
    //     std::cout << S[i] << " ";
    // }
    // cout << endl;
    //  for (int i = 0; i < N; i++) {
    //     std::cout << D[i] << " ";
    // }
    // cout << endl;

    answer(S, D);
}

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