Submission #937734

#	Time	Username	Problem	Language	Result	Execution time	Memory
937734		Alcabel	Combo (IOI18_combo)	C++17	100 / 100	15 ms	1844 KiB

combo

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

string guess_sequence(int N) {
    string s = "", p = "", lets = "ABXY";
    p += lets[0];
    p += lets[1];
    // cerr << "p: " << p << '\n';
    if (press(p)) {
        p = lets[0];
        // cerr << "p: " << p << '\n';
        if (press(p)) {
            s += lets[0];
        } else {
            s += lets[1];
        }
    } else {
        p = lets[2];
        // cerr << "p: " << p << '\n';
        if (press(p)) {
            s += lets[2];
        } else {
            s += lets[3];
        }
    }
    // cerr << "first: " << s << '\n';
    for (int i = 0; i < 4; ++i) {
        if (lets[i] == s[0]) {
            swap(lets[i], lets.back());
            lets.pop_back();
            break;
        }
    }
    for (int i = 0; i < N - 2; ++i) {
        p = s + lets[0];
        p += s + lets[1] + lets[0];
        p += s + lets[1] + lets[1];
        p += s + lets[1] + lets[2];
        // cerr << "i: " << i << ", p: " << p << '\n';
        int len = press(p);
        // cerr << "len: " << len << '\n';
        if (len == (int)s.size() + 1) {
            s += lets[0];
        } else if (len == (int)s.size() + 2) {
            s += lets[1];
        } else {
            s += lets[2];
        }
    }
    // cerr << "last: " << s << '\n';
    // cerr << "p: " << s + lets[0] + s + lets[1] << '\n';
    if (N > 1) {
        if (press(s + lets[0] + s + lets[1]) == N) {
            if (press(s + lets[0]) == N) {
                s += lets[0];
            } else {
                s += lets[1];
            }
        } else {
            s += lets[2];
        }
    }
    return s;
}

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