Submission #1020122

#	Time	Username	Problem	Language	Result	Execution time	Memory
1020122		Issa	Combo (IOI18_combo)	C++17	100 / 100	24 ms	1848 KiB

combo

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

int press(std::string p);

string guess_sequence(int N){
	if(N == 1){
		if(press("A")) return "A";
		if(press("B")) return "B";
		if(press("X")) return "X";
		return "Y";
	}
	vector<string> t = {"A", "B", "X", "Y"};
	string s;
	if(press("AB")){
		if(press("A")) s = "A";
		else s = "B";
	} else{
		if(press("X")) s = "X";
		else s = "Y";
	}
	for(string &c: t){
		if(c == s){
			swap(c, t.back());
			break;
		}
	}
	t.pop_back();
	for(int i = 2; i < N; i++){
		int x = press(s + t[0] + t[0] + s + t[0] + t[1] + s + t[0] + t[2] + s + t[1]);
		s += t[2 - (x - i + 1)];
	}
	if(press(s + t[0]) == N) s += t[0];
	else if(press(s + t[1]) == N) s += t[1];
	else s += t[2];
	return s;
}

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