Submission #774486

#	Time	Username	Problem	Language	Result	Execution time	Memory
774486		Alfraganus	Combo (IOI18_combo)	C++14	100 / 100	27 ms	572 KiB

combo

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

string guess_sequence(int n){
    string s = "AB", t, d;
    if(press(s)){
        s = "A";
        t = press(s) ? "A" : "B";
    }
    else{
        s = "X";
        t = press(s) ? "X" : "Y";
    }

    if(n == 1)return t;
    for(auto &x : "ABXY")if(x != t[0])d.push_back(x);
    for(int i = 1; i < n - 1; i ++){
        s = t;
        s += d[0];
        s += t;
        s += d[1];
        s += d[0];
        s += t;
        s += d[1];
        s += d[1];
        s += t;
        s += d[1];
        s += d[2];
        int res = press(s);
        if(res <= i)t += d[2];
        else if(res == i + 1)t += d[0];
        else t += d[1];
    }
    s = t;
    s += d[0];
    if(press(s) == n)return s;
    s = t;
    s += d[1];
    if(press(s) == n)return s;
    t += d[2];
    return t;
}

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