Submission #107216

#	Time	Username	Problem	Language	Result	Execution time	Memory
107216		nickyrio	Cave (IOI13_cave)	C++17	100 / 100	458 ms	504 KiB

cave

#include "cave.h"
#include <cstdio>

void exploreCave(int N) {
    int S[N], D[N];
    for (int i = 0; i < N; ++i) S[i] = 0, D[i] = -1;
    for (int i = 0; i < N; ++i) {
        int l = 0, r = N - 1, pos = N;

        int res = tryCombination(S);   
        if (res == -1) res = N + 1;
        if (res > i) {
            for (int j = 0; j < N; ++j) if (D[j] == -1) S[j] ^= 1;
        }
        while (l <= r) {
      //      printf("L = %d, R = %d", l, r);
            int m = (l + r) >> 1;
            for (int j = l; j <= m; ++j) if (D[j] == -1) S[j] ^= 1;

            res = tryCombination(S);
            if (res == -1) res = N + 1;
        //    printf("Res = %d\n", res);
            if (res > i) {
                // Door i is open
                pos = m;
                r = m;  
                if (l == r) break;
            } else l = m + 1;
            for (int j = l; j <= m; ++j) if (D[j] == -1) S[j] ^= 1;
        }
        D[pos] = i;
        //printf("Switch %d is connected with door %d\n", pos, i);
    }
    answer(S, D);
}

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