Submission #642811

#	Time	Username	Problem	Language	Result	Execution time	Memory
642811		Alexandruabcde	Combo (IOI18_combo)	C++14	100 / 100	37 ms	568 KiB

combo

#include "combo.h"
#include <bits/stdc++.h>

using namespace std;

char First;
string letters;

char FindFirst () {
    if (press("AB") != 0) {
        if (press("A")) return 'A';

        return 'B';
    }

    if (press("X")) return 'X';

    return 'Y';
}

string ans;

char FindCaracter (int sz) {
    string query = ans + letters[0] + ans + letters[1] + letters[0] + ans + letters[1] + letters[1] + ans + letters[1] + letters[2];

    int lg = press(query);

    if (lg == sz + 1) return letters[1];

    if (lg == sz) return letters[0];

    return letters[2];
}

char FindLast (int N) {
    string query = ans + letters[0];
    int lg = press(query);
    if (lg == N) return letters[0];

    query = ans + letters[1];
    lg = press(query);
    if (lg == N) return letters[1];

    return letters[2];
}

std::string guess_sequence(int N) {
    First = FindFirst();
    ans = "";

    if (First == 'A') letters = "BXY";
    if (First == 'B') letters = "AXY";
    if (First == 'X') letters = "ABY";
    if (First == 'Y') letters = "ABX";

    ans = First;

    if (N == 1) return ans;

    for (int i = 2; i < N; ++ i )
        ans += FindCaracter(i);

    ans += FindLast(N);

    return ans;
}

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