Submission #1075353

#	Time	Username	Problem	Language	Result	Execution time	Memory
1075353		juicy	Combo (IOI18_combo)	C++17	100 / 100	23 ms	1852 KiB

combo

#include "combo.h"

#include <bits/stdc++.h>

std::string guess_sequence(int n) {
    std::string c = "ABXY", cands, s;
    if (!press("AB")) {
        s = press("X") ? "X" : "Y";
    } else {
        s = press("A") ? "A" : "B";
    }
    if (n == 1) {
        return s;
    }
    for (int i = 0; i < 4; ++i) {
        if (c[i] != s[0]) {
            cands += c[i];
        }
    }
    for (int i = 1; i + 1 < n; ++i) {
        auto msg = s + cands[1] + s + cands[2] + cands[0] + s + cands[2] + cands[1] + s + cands[2] + cands[2];
        int ind = press(msg) - s.size();
        s += cands[ind];
    }
    if (press(s + cands[1]) == n) {
        return s + cands[1];
    }
    return press(s + cands[0]) == n ? s + cands[0] : s + cands[2];
}

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