Submission #536416

#	Time	Username	Problem	Language	Result	Execution time	Memory
536416		timreizin	Combo (IOI18_combo)	C++17	100 / 100	64 ms	548 KiB

combo

#include "combo.h"
#include <vector>
#include <algorithm>

using namespace std;

string guess_sequence(int n)
{
    string s = "";
    if (press("AB") >= 1)
    {
        if (press("A") >= 1) s += 'A';
        else s += 'B';
    }
    else
    {
        if (press("X") >= 1) s += 'X';
        else s += 'Y';
    }
    if (n == 1) return s;
    vector<char> chars{'A', 'B', 'X', 'Y'};
    chars.erase(find(chars.begin(), chars.end(), s.front()));
    for (int i = 1; i + 1 < n; ++i)
    {
        int c = press(s + chars[0] + s + chars[1] + chars[0] + s + chars[1] + chars[1] + s + chars[1] + chars[2]);
        if (c == i) s += chars[2];
        else if (c == i + 1) s += chars[0];
        else s += chars[1];
    }
    if (press(s + 'A' + s + 'B') == n)
    {
        if (press(s + 'A') == n) s += 'A';
        else s += 'B';
    }
    else
    {
        if (press(s + 'X') == n) s += 'X';
        else s += 'Y';
    }
    return s;
}

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