Submission #1193370

#	Time	Username	Problem	Language	Result	Execution time	Memory
1193370		Ormlis	Combo (IOI18_combo)	C++20	100 / 100	7 ms	492 KiB

combo

#include "combo.h"
#include <iostream>

std::string guess_sequence(int N) {
    std::string letters = "ABXY";
    if (N == 1) {
        for (int i = 0; i < 4; ++i) {
            if (i == 3 || press(letters.substr(i, 1)) == 1) {
                return letters.substr(i, 1);
            }
        }
    }
    std::string result;
    if (press("AB")) {
        if (press("A")) {
            result += "A";
        } else {
            result += "B";
        }
    } else {
        if (press("X")) {
            result += "X";
        } else {
            result += "Y";
        }
    }
    letters.erase(letters.find(result[0]), 1);
    for (int i = 1; i + 1 < N; ++i) {
        std::string query;
        for (int c = 0; c < 3; ++c) {
            query += result;
            query += letters[2];
            query += letters[c];
        }
        query += result;
        query += letters[1];
        result += letters[press(query) - i];
    }
    if (press(result + letters[0]) == N) {
        result += letters[0];
    } else if (press(result + letters[1]) == N) {
        result += letters[1];
    } else {
        result += letters[2];
    }

    return result;
}

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