Submission #991843

#	Time	Username	Problem	Language	Result	Execution time	Memory
991843		phoenix	Combo (IOI18_combo)	C++17	100 / 100	35 ms	1804 KiB

combo

#include "combo.h"

using namespace std;

string guess_sequence(int N) {
	string S;
	if (press("AB")) {
		if (press("A"))
			S += 'A';
		else 
			S += 'B';
	} else {
		if (press("X"))
			S += 'X';
		else 
			S += 'Y';
	}
	string t = "ABXY";
	t.erase(t.find(S[0]), 1);

	for (int i = 1; i < N - 1; i++) {
		string p = "";
		p += S + t[0];
		p += S + t[1] + t[0];
		p += S + t[1] + t[1];
		p += S + t[1] + t[2];
		int x = press(p) - (int)S.size();
		if (x == 0) S += t[2];
		if (x == 1) S += t[0];
		if (x == 2) S += t[1];
	}
	if ((int)S.size() < N) {
		if (press(S + t[0] + S + t[1]) == N) {
			if (press(S + t[0]) == N) 
				S += t[0];
			else S += t[1];
		} else {
			S += t[2];
		}
	}
	return S;
}

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