Submission #413587

#	Time	Username	Problem	Language	Result	Execution time	Memory
413587		timmyfeng	Combo (IOI18_combo)	C++17	100 / 100	47 ms	636 KiB

combo

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

#include "combo.h"

string guess_sequence(int n) {
    string ans;
    if (press("AB") > 0) {
        ans = press("A") > 0 ? "A" : "B";
    } else {
        ans = press("X") > 0 ? "X" : "Y";
    }

    if (n == 1) {
        return ans;
    }

    string buttons = "ABXY";
    buttons.erase(find(buttons.begin(), buttons.end(), ans[0]));

    for (int i = 1; i < n - 1; ++i) {
        string ask = ans + buttons[1];
        for (int j = 0; j < 3; ++j) {
            ask += ans + buttons[2] + buttons[j];
        }

        int res = press(ask);

        for (int j = 0; j < 3; ++j) {
            if (res == i + j) {
                ans += buttons[j];
            }
        }
    }

    for (int i = 0; i < 2; ++i) {
        if (press(ans + buttons[i]) == n) {
            return ans + buttons[i];
        }
    }

    return ans + buttons[2];
}

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