Submission #726142

#	Time	Username	Problem	Language	Result	Execution time	Memory
726142		colossal_pepe	Cave (IOI13_cave)	C++17	100 / 100	617 ms	480 KiB

cave

#include "cave.h"
#include <iostream>
#include <cstring>
using namespace std;

int n;

void makeCombination(int s, int m, int S[], int S_try[]) {
    for (int i = 0; i <= m; i++) {
        S_try[i] = (S[i] == -1 ? s : S[i]);
    }
    for (int i = m + 1; i < n; i++) {
        S_try[i] = (S[i] == -1 ? !s : S[i]);
    }
    // cout << "----" << endl;
    // for (int i = 0; i < n; i++) {
    //     cout << S_try[i] << ' ';
    // }
    // cout << endl;
    // cout << "----" << endl;
}

bool isOpen(int door, int S_try[]) {
    int reached = tryCombination(S_try);
    if (reached == -1) reached = n;
    return door < reached;
}

int openStateOf(int door, int S[], int S_try[]) {
    makeCombination(1, n - 1, S, S_try);
    return isOpen(door, S_try);
}

int switchOf(int door, int s, int S[], int S_try[]) {
    int l = 0, r = n - 1;
    while (r - l > 1) {
        int m = (l + r) / 2;
        makeCombination(s, m, S, S_try);
        if (isOpen(door, S_try)) r = m;
        else l = m + 1;
    }
    if (r == l) return l;
    makeCombination(s, l, S, S_try);
    if (isOpen(door, S_try)) return l;
    return r;

}

void exploreCave(int N) {
    n = N;
    int S[n], D[n], S_try[n];
    memset(S, -1, sizeof S);
    memset(D, -1, sizeof D);
    for (int i = 0; i < n; i++) {
        int s = openStateOf(i, S, S_try);
        int d = switchOf(i, s, S, S_try);
        S[d] = s;
        D[d] = i;
    }
    answer(S, D);
}

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