Submission #254180

#	Time	Username	Problem	Language	Result	Execution time	Memory
254180		AaronNaidu	Cave (IOI13_cave)	C++14	100 / 100	434 ms	504 KiB

cave

#include <bits/stdc++.h>
#include "cave.h"
using namespace std;

int N;


int doDoor(int door, int s[], int d[], bool fixed[]) {
    int upperLimit = N-1;
    int lowerLimit = 0;
    int b;
    for (int i = 0; i < N; i++)
    {
        if (!fixed[i])
        {
            s[i] = 1;
        }
    }
    int t = tryCombination(s);
    if (t == door) //door is closed on a 1
    {
        b = 1;
    }
    else
    {
        b = 0;
    }
    for (int i = 0; i < N; i++)
    {
        if (!fixed[i])
        {
            s[i] = 1-b;
        }
    }

    while (upperLimit > lowerLimit)
    {
        int midpoint = (upperLimit + lowerLimit)/2;
        for (int i = lowerLimit; i <= midpoint; i++)
        {
            if (!fixed[i])
            {
                s[i] = b;
            }
        }
        int x = tryCombination(s);
        if (x == door) //case where door closed
        {
            upperLimit = midpoint;
        }
        else //case where door opened
        {
            lowerLimit = midpoint+1;
        }
        
        for (int i = lowerLimit; i <= midpoint; i++)
        {
            if (!fixed[i])
            {
                s[i] = 1-b;
            }
            
        }
    }
    return lowerLimit;
}

void exploreCave(int n) {
    int s[n];
    int d[n];
    bool fixed[n];
    N = n;
    for (int i = 0; i < n; i++)
    {
        s[i] = 0;
        d[i] = 0;
        fixed[i] = false;
    }
    
    for (int i = 0; i < n; i++)
    {
        int ans = doDoor(i, s, d, fixed);
        d[ans] = i;
        fixed[ans] = true;
    }
    answer(s, d);
}

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