Submission #729812

#	Time	Username	Problem	Language	Result	Execution time	Memory
729812		2vas	Combo (IOI18_combo)	C++17	0 / 100	72 ms	208 KiB

combo

// Source: https://usaco.guide/general/io

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


string guess_sequence(int N) {
	// get first letter
	int n = N;

	char first;
	char other[3];

	if (press("AB")) {
		if (press("A")) {
			first = 'A';
			other[0] = 'B';
			other[1] = 'X';
			other[2] = 'Y';
		} else {
			first = 'B';
			other[0] = 'A';
			other[1] = 'X';
			other[2] = 'Y';
		}
	} else {
		if (press("X")) {
			first = 'X';
			other[0] = 'B';
			other[1] = 'A';
			other[2] = 'Y';
		} else {
			first = 'Y';
			other[0] = 'A';
			other[1] = 'X';
			other[2] = 'B';
		}
	}

	string s = "" + first;

	while ((int) s.length() < n - 1) {
		string p = s + other[0] + other[1];
		p += s + other[0] + other[2];
		p += s + other[1] + other[2];
		int v = press(p);

		if (v == 0 + (int) s.length()) {
			s += other[2];
			continue;
		}

		if (v == 1 + (int) s.length()) {
			p = s + other[1] + other[1];
			v = press(p);
			if (v == 0 + (int) s.length()) {
				s += other[0] + other[0];
			} else if (v == 1 + (int) s.length()) {
				s += other[1] + other[0];
			} else {
				// assert(v == 2 + (int) s.length());
				s += other[1] + other[1];
			}
			continue;
		}

		if (v == 2 + (int) s.length()) {
			p = s + other[0] + other[1];
			v = press(p);
			if (v == 0 + (int) s.length()) {
				s += other[1] + other[2];
			} else if (v == 1 + (int) s.length()) {
				s += other[0] + other[2];
			} else {
				// assert(v == 2 + (int) s.length());
				s += other[0] + other[1];
			}
			continue;
		}
	}

	if ((int) s.length() == n) {
		return s;
	}


	if (press(s + other[0] + s + other[1]) == n) {
		if (press(s + other[0]) == n) {
			s += other[0];
		} else {
			s += other[1];
		}
	} else {
		s += other[2];
	}

	return s;

}

• Subtask 1: 0 / 5
• Subtask 2: 0 / 95