Submission #835315

#	Time	Username	Problem	Language	Result	Execution time	Memory
835315		mousebeaver	Combo (IOI18_combo)	C++14	97 / 100	26 ms	716 KiB

combo

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

std::string guess_sequence(int N) 
{
    vector<string> a(0);
    string prefix = "";

    if(press("AB") > 0)
    {
        if(press("A") == 1)
        {
            a = {"B", "X", "Y"};
            prefix = "A";
        }
        else
        {
            a = {"A", "X", "Y"};
            prefix = "B";
        }
    }
    else
    {
        if(press("X") == 1)
        {
            a = {"B", "A", "Y"};
            prefix = "X";
        }
        else
        {
            a = {"A", "X", "B"};
            prefix = "Y";
        }
    }
    if(N == 1)
    {
        return prefix;
    }

    while((int) prefix.length() < N-1)
    {
        string q = prefix + a[1] + prefix + a[2] + a[0] + prefix + a[2] + a[1] + prefix + a[2] + a[2];
        int res = press(q);
        if(res == (int) prefix.length())
        {
            prefix += a[0];
        }
        else if(res == (int) prefix.length()+1)
        {
            prefix += a[1];
        }
        else
        {
            prefix += a[2];
        }
    }

    int index = 0;
    while(press(prefix+a[index]) < N)
    {
        index++;
    }
    prefix += a[index];

    return prefix;
}

• Subtask 1: 5 / 5
• Subtask 2: 92 / 95