Submission #648041

#	Time	Username	Problem	Language	Result	Execution time	Memory
648041		Clan328	Cave (IOI13_cave)	C++17	0 / 100	54 ms	448 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 curr, int lo, int mid, int hi) {
    int arr[n];
    for (int i = lo; i <= mid; i++) {
        if (dir[i] == NA) arr[i] = dir[curr];
        else arr[i] = dir[i];
    }
     for (int i = mid+1; i <= hi; i++) {
        if (arr[i] == NA) arr[i] = 1-dir[curr];
    }

    return tryCombination(arr);
}

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

    n = N;

    for (int i = 0; i < N; i++) {
        for (int j = 0; j < N; j++) {
            S[j] = dir[j];
            if (S[j] == NA) S[j] = DOWN;
        }

        int tmp = tryCombination(S);
        if (tmp == i) {
            dir[i] = DOWN;
        } else
            dir[i] = UP;

        int lo = 0, hi = N-1, mid;
        while (lo < hi) {
            mid = (lo+hi)/2;

            bool isDownI = check(i, lo, mid, hi) == i;

            if (isDownI) {
                hi = mid;
            } else
                lo = mid + 1;
        }

        D[lo] = i+1;
    }

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

    answer(S, D);
}

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