Submission #683112

#	Time	Username	Problem	Language	Result	Execution time	Memory
683112		bebra	Combo (IOI18_combo)	C++17	5 / 100	1 ms	284 KiB

combo

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

#define dbg(x) cerr << #x << ": " << x << endl;


const char chars[] = {'A', 'B', 'X', 'Y'};

int press(string p);

string guess_sequence(int n) {
    char first_char;
    if (press("AB")) {
        if (press("A")) {
            first_char = 'A';
        } else {
            first_char = 'B';
        }
    } else {
        if (press("X")) {
            first_char = 'X';
        } else {
            first_char = 'Y';
        }
    }
    string good;
    for (auto c : chars) {
        if (c != first_char) good += c;
    }

    string res = string(1, first_char);
    for (int i = 2; i <= n - 1; ++i) {
        string t;
        t += res + good[0];
        t += res + good[1] + good[0];
        t += res + good[1] + good[1];
        t += res + good[1] + good[2];
        int len = press(t);

        if (len == i) {
            res += good[0];
        } else if (len == i + 1) {
            res += good[1];
        } else {
            res += good[2];
        }
    }

    if (press(res + good[0]) == n) {
        res += good[0];
    } else {
        if (press(res + good[1]) == n) {
            res += good[1];
        } else {
            res += good[2];
        }
    }
    return res;
}

• Subtask 1: 5 / 5
• Subtask 2: 0 / 95