Submission #650738

#	Time	Username	Problem	Language	Result	Execution time	Memory
650738		erke	Combo (IOI18_combo)	C++11	100 / 100	36 ms	692 KiB

combo

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

int press(string p);

string guess_sequence(int n) {
    vector<char> v = {'A', 'B', 'X', 'Y'};
    string ret;
    if (press("AB")) {
        if (press("A")) {
            ret += 'A';
            swap(v[0], v[3]);
        }
        else {
            ret += 'B';
            swap(v[1], v[3]);
        }
    }
    else {
        if (press("X")) {
            ret += 'X';
            swap(v[2], v[3]);
        }
        else {
            ret += 'Y';
            // swap(v[3], v[3]);
        }
    }
    while ((int) ret.size() < n - 1) {
        string tmp = ret + v[0];
        for (int i = 0; i < 3; i++) {
            tmp += ret + v[1] + v[i];
        }
        int p = press(tmp);
        if (p == (int) ret.size() + 1) {
            ret += v[0];
        }
        else if (p == (int) ret.size() + 2) {
            ret += v[1];
        }
        else {
            ret += v[2];
        }
    }
    if (n > 1) {
        if (press(ret + v[0]) == n) {
            ret += v[0];
        }
        else if (press(ret + v[1]) == n) {
            ret += v[1];
        }
        else {
            ret += v[2];
        }
    }
    return ret;
}

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