Submission #567589

#	Time	Username	Problem	Language	Result	Execution time	Memory
567589		valerikk	Combo (IOI18_combo)	C++17	30 / 100	50 ms	444 KiB

combo

#include "combo.h"
#include <vector>
#include <string>
#include <algorithm>

std::string guess_sequence(int N) {
	static const char buttons[] = { 'A', 'B', 'X', 'Y' };

	int first;

	if (press(std::string { buttons[0], buttons[1] })) {
		if (press(std::string { buttons[0] })) {
			first = 0;
		} else {
			first = 1;
		}
	} else {
		if (press(std::string { buttons[2] })) {
			first = 2;
		} else {
			first = 3;
		}
	}

	char Y = buttons[first];
	char A = buttons[(first + 1) & 3];
	char B = buttons[(first + 2) & 3];
	char X = buttons[(first + 3) & 3];

	std::string S { Y };

	for (int i = 1; i < N; ++i) {
		if (press(S + A + S + B) == i + 1) {
			if (press(S + A) == i + 1) {
				S += A;
			} else {
				S += B;
			}
		} else {
			if (press(S + B) == i + 1) {
				S += B;
			} else {
				S += X;
			}
		}
	}

	return S;
}

• Subtask 1: 5 / 5
• Subtask 2: 25 / 95