Submission #367787

#	Time	Username	Problem	Language	Result	Execution time	Memory
367787		idk321	Cave (IOI13_cave)	C++11	100 / 100	1074 ms	736 KiB

cave

#include "cave.h"

const int N = 5000;
int s[N];
int d [N];
bool skip [N];
int n;

void change(int to)
{
    for (int i = 0; i <= to; i++)
    {
        if (!skip[i])
        {
            s[i] = !s[i];
        }
    }
}

int bs(bool org, int i)
{
    int a = 0;
    int b = n - 1;
    int res = -1;
    while (a <= b)
    {
        int mid = (a + b) / 2;
        change(mid);
        bool cgood = false;
        int cur = tryCombination(s);
        if (cur == - 1 || cur > i) cgood = true;
        if (cgood != org)
        {
            res = mid;
            b = mid - 1;
        } else
        {
            a = mid + 1;
        }
        change(mid);
    }

    return res;
}

void exploreCave(int N) {
    n = N;

    for (int i = 0; i < n; i++)
    {
        int cur = tryCombination(s);
        bool good = false;
        if (cur == -1 || cur > i) good = true;

        int ind = bs(good, i);
        skip[ind] = true;
        if (!good) s[ind] = !s[ind];
        d[ind] = i;
    }

    answer(s, d);
}

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