Submission #247063

#	Time	Username	Problem	Language	Result	Execution time	Memory
247063		arbor	Cave (IOI13_cave)	C++14	100 / 100	454 ms	632 KiB

cave

#include "cave.h"
#include <bits/stdc++.h>
bool done[5005];

int get(int S[]) {
    int ret = tryCombination(S);
    if (ret == -1) ret = 5001;
    return ret;
}

void exploreCave(int N) {
    int s[N], d[N];
    memset(s, 0, sizeof(s));
    for (int i = 0; i < N; i++) {
        int l = 0, r = N - 1;
        // assume doors [0, i-1] are already open
        for (int j = 0; j < N; j++) if (!done[j]) s[j] = 0;
        bool state = get(s) == i;
        for (int j = 0; j < N; j++) if (!done[j]) s[j] = !state;
        while (l < r) {
            int m = (l + r) / 2;
            for (int j = l; j <= m; j++)
                if (!done[j]) s[j] = state;
            int idx = get(s);
            for (int j = l; j <= m; j++)
                if (!done[j]) s[j] = !state;
            if (idx == i) l = m + 1;
            else r = m;
        }
        s[l] = state;
        d[l] = i;
        done[l] = true;
    }
    answer(s, d);
}

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