Submission #839661

#	Time	Username	Problem	Language	Result	Execution time	Memory
839661		sleepntsheep	Combo (IOI18_combo)	C++17	100 / 100	29 ms	540 KiB

combo

#include "combo.h"
#include <cassert>
#include <string>
#include <vector>
using namespace std;

string guess_sequence(int N)
{
    string S, opt;

    if (press("AB"))
    {
        if (press("A")) opt="BXY", S="A";
        else opt="AXY", S="B";
    }
    else
    {
        if (press("X")) opt="ABY", S="X";
        else opt="ABX", S="Y";
    }

    if (N == 1) return S;

    for (int i = 1; i < N - 1; ++i)
    {
        string ask = S + opt[0] + opt[0] + S + opt[0] + opt[1] + S + opt[0] + opt[2]  + S + opt[1];
        int k = press(ask);
        if (k == i + 2) S += opt[0];
        else if (k == i + 1) S += opt[1];
        else S += opt[2];
    }

    if (press(S+opt[0])==N) S+=opt[0];
    else if (press(S+opt[1])==N) S+=opt[1];
    else S+=opt[2];

    return S;
}

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